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LUMBER GRADING TRAINING MANUAL


LUMBER GRADING TRAINING MANUAL Guide to General Instructions and Standard Grades of Measurement and Inspection of Hardwood Lumber

National Hardwood Lumber Association PO Box 34518 | Memphis, TN 38184-0518 | 901-377-1818 | 901-382-6419 Fax www.nhla.com

Š 2006 by the National Hardwood Lumber Association. Reproduction in whole or in part without expressed permission of the association, or any other unauthorized use, is not permitted.


FOREWORD This manual is designed to supplement the hands-on instruction of the 14-week course in lumber grading, taught on a vocational level, at the NHLA Inspector Training School in Memphis, Tennessee. The manual is cross-referenced to the Association’s official Rule Book (2007), Rules for the Measurement and Inspection of Hardwood and Cypress, and is intended to clarify major points through the use of diagrams and additional explanation. It will also serve as a reference on some of the more involved concepts in lumber grading and allows the student to go beyond the language in the official Rule Book. This will be a helpful text for home study or independent study at your place of business in training newly hired or experienced employees. The diagrams illustrate major points of the cutting unit system and the basic requirements for the standard grades.

TABLE OF CONTENTS Development of Hardwood Lumber Grades. . . . . . . . . . . . . 3

Tapering Lumber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Selects — 6” and Wider Wane Limitations . . . . . . . . . . . . . .40

Cutting Unit Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Standard Grades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Summary of Wane Limitations . . . . . . . . . . . . . . . . . . . . . . . . . 41

How Boards Are Graded. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Summary of Standard Grades . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Summary of the Standard Grades — No. 1 Common . . . . . 41

General Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Summary of Six Defect Limitations . . . . . . . . . . . . . . . . . . . . . . 25

Special Yields — No. 1 Common . . . . . . . . . . . . . . . . . . . . . . . . 42

Cuttings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Sample FAS Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Sample No. 1 Common Boards . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Clear-Face Cuttings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

FAS — Pith Limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

No. 1 Common — Pith Limitation . . . . . . . . . . . . . . . . . . . . . . . 43

Sound Cutting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

FAS Wane Limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Summary of the Standard Grades —

Surface Measure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

FAS Split Limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Board Feet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

FAS First Lineal Foot Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Sample No. 2A Common. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Cutting Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

FAS Knot Limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Special Yields — No. 2A and 2B Common. . . . . . . . . . . . . . . . 44

Cutting Unit Worksheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Finding Average Diameter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Sample No. 2B Common. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Standard Lengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

FAS Warp and Cup Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Summary of the Standard Grades — No. 3A Common. . . . 45

Standard Rough Thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

FAS One Face . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Summary of the Standard Grades — No. 3B Common. . . . 46

Standard Surfaced Thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

FAS 1 FACE (F1F) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Standard Kiln Dried Rule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Miscut Lumber Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

FAS1F — Wane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Inspection of Kiln Dried Lumber Measurement

Minimum Width Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Summary of the Standard Grades — Selects . . . . . . . . . . . . 36

Determining the Width of a Board . . . . . . . . . . . . . . . . . . . . . . 19

Selects — FAS Face . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Measurement Before Kiln Drying. . . . . . . . . . . . . . . . . . . . . . . . 47

Choosing the Grading Face . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Selects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Hardwood Lumber Grades Standard Inspection. . . . . . . . . . 48

Effect of Unsound Defects on Reverse Side of Cuttings. . . 22

Selects — 4” and 5” Wane Limitation . . . . . . . . . . . . . . . . . . . 38

No. 2A and No. 2B Common . . . . . . . . . . . . . . . . . . 43

After Kiln Drying. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

National Hardwood Lumber Association

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DEVELOPMENT OF HARDWOOD LUMBER GRADING RULES In the late 1800s in North America, the hardwood industry was well developed and hardwood lumber products were used both locally and in distant markets for a variety of uses. Customarily, only the highest grade of hardwood lumber was shipped over any distance, and there was only one grade, and that was “clear.” However, with the growth of the secondary wood processing industries and the multiplicity of products in which hardwood lumber could be put to use, circumstances gradually developed that required a more formalized inspection and grading system. Because there was little personal contact between buyer and seller over these great distances, sometimes it was difficult to arrive at a meeting of the minds, and buyer and seller could not agree upon exactly what specification was ordered or shipped. In addition, a need for standard nomenclature was realized since the highest grade in one market might not be known as “clear,” while the highest grade using essentially the same specification could be known as “good” in other areas of the country. In 1898, well-intentioned lumbermen from various parts of the country met in Chicago, Illinois and founded the National Hardwood Lumber Association with the intention of establishing uniform rules for the measurement and inspection of hardwood lumber which could serve markets all over the country. As might be expected, there was considerable resistance from local markets and also regional lumber associations at first, but over the years their differences were reconciled and by 1908, National rules became accepted by both sawmillers and wholesalers in most markets. From the beginning, NHLA employed National inspectors whose services could be used on a voluntary basis in many of the regional markets, including Memphis, New Orleans, Boston, New York, Baltimore, Buffalo, and Philadelphia. However, the Association had difficulty placing inspectors in smaller markets since the low volume of trade would not support the inspector’s salary. In addition, the Association had problems due to misinterpretation of the National rules by private inspectors, and therefore, in 1948 established a school for hardwood lumber inspectors in order to impart a basic understanding of the rules in the trade and to promote uniform application of the rules in practice. The modern NHLA school was established in 1948, and today, the NHLA Inspector Training School in Memphis, Tennessee, has graduated over 6,700 beginning lumber inspectors, who continue to have an influence on the hardwood lumber industry. The National Inspection Service still serves as the final authority on the application of the grades, and NHLA’s staff of well qualified inspectors can be called in by members and non-members alike to provide expert third-party inspection of lumber at origin or destination, by the mutual agreement of buyer and seller in order to mediate any disputes.

National Hardwood Lumber Association

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THE CUTTING UNIT METHOD The cutting unit method is the very foundation upon which the hardwood lumber grades are based. Using this step-by-step process, a mathematical comparison between the total amount of wood in a board and the amount of usable wood in that same board can be made. The boards can then be separated into groupings based on the percentage of usable wood a board will actually yield. These groupings are most commonly referred to as “grades.” The Cutting Unit Method for grading hardwood lumber has provided a common ground for both the manufacturers of hardwood lumber and the users of hardwood lumber to conduct business. The beauty of the cutting unit system lies in two fundamental characteristics. First, the grades that result do not depend upon someone to form an opinion, therefore, the grades are not “appearance” grades where interpretations could vary from inspector to inspector. The proof of the grade lies in a mathematical computation, not a matter of opinion. Second, the grading system models or approximates the actual breakdown of lumber in the manufacturing process of most furniture plants, flooring facilities, or millwork houses. The cutting unit system estimates crosscuts and rip cuts which would occur if the board was being cut up into components for the final product. A manufacturer of products which requires large clear or sound pieces can purchase just the grades of lumber that will yield the needed pieces. Manufacturers who use smaller pieces may buy the less expensive grades of lumber which yield the pieces they require.

HOW BOARDS ARE GRADED The Steps in Grading Lumber:

1. Determine the Surface Measure (SM) using a board rule (lumber scaling stick).

2. Determine the poor side of the board. In cutting grades, the poor side of the board is determined by the side with the lower grade, or if both sides have the same grade, it is the side with the least number of cutting units.

3. Assign a “trial” grade to the poor face, based on your estimate of the yield of clear wood in legal size cuttings.

4. Determine number of cuttings permitted in the “trial” grade, keeping in mind the minimum size of cutting required for that grade.

5. Determine the clear-face cutting units needed (SM x the multiplier for that grade).

6. Calculate the total area of clear-face cutting units on the poor face.

7. If the board does not yield sufficient clear-face cutting units of the right size and number of cuttings, try the next lower grade. Remember the reverse side of the clear- face cuttings must be sound.

8. Tally SM by grade and thickness on basis of 1” (4/4) lumber.

In lumber thicker than 1” the tally in BF is multiplied by the thickness as expressed in inches and fractions of an inch. Lumber less than 1” thick is measured and tallied as 1” lumber.

National Hardwood Lumber Association

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GENERAL INSTRUCTIONS The General Instructions characterize how lumber should be manufactured. These rules apply “in general” to all lumber, setting the standards for the qualities of good lengths, widths, and thicknesses. “Inspectors are instructed to study these rules carefully and use their best judgment in applying them, but shall not allow their judgment to supersede anything specifically stated in the rules themselves.” (Paragraph 1)* “Lumber shall be inspected and measured as the inspector finds it, of full length, width and thickness.” (Paragraph 4) Hardwood lumber is usually sawn random width, that is, the decision of when to turn the log on the carriage is made on the basis of obtaining the most clear material in each board, rather than obtaining “stock” widths (for example 4”, 6”, 8”, and 10” wide, etc.) as in softwood lumber. By the same reasoning, boards are edged, not to “stock” widths, but only enough to remove excess wane, and leave the most amount of usable material remaining in a board. Because hardwood lumber is ultimately cut up in smaller pieces by the end user, and the dimensions of that final piece vary widely among and between users, there is no great advantage to stock widths. * NOTE: A  ll references to paragraph numbers apply to the 2007 edition of “Rules for the Measurement and Inspection of Hardwood and Cypress,” © 2005 by the National Hardwood Lumber Association.

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CUTTINGS A cutting is a “portion of a board or plank obtained by crosscutting or ripping or by both. In the “C” common grades, a cutting shall be flat enough to surface two sides to standard surfaced thickness after it has been removed from the board. In the grades of Selects and Better the entire board shall be flat enough to surface two sides to standard surfaced thickness. Diagonal cuttings are not permitted” (Paragraph 29). In the illustration below there are three cuttings drawn. The lines outlining the cuttings represent the crosscuts and rips that would be necessary to remove the cuttings from the board. It should be well understood that when taking cuttings on a board, an inspector does not physically saw the pieces from the board. A cutting is simply a measurement of width and length. The shaded areas represent defects or unusable material, which by definition are not included in the cutting.

Cuttings #2 and #3 are permitted, however, since cutting #1 does not parallel an edge of the board it would be considered a diagonal cutting and “Diagonal cuttings are not permitted.” Cuttings are further categorized as clear-face cuttings and sound cuttings. In the following example, 5 cuttings are used. Cuttings number 1, 2, 4, and 5 are rips and cutting number 3 is a crosscut. Notice that all 5 cuttings are parallel to at least one edge of the board and are rectangular in shape. All 5 cuttings could be used when grading a board.

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CLEAR-FACE CUTTINGS “A cutting having one clear face (ordinary season checks are admitted) and the reverse side sound as defined in Sound Cutting. The clear face of the cutting shall be on the poor side of the board except when otherwise specified” (Paragraph 30). As stated in the definition, a clear-face cutting is a cutting having one clear or defect-free face with the reverse side free from any unsound defects. The clear face of the cutting must be on the poor side of the board unless the grading rules state otherwise. The concept behind clear-face cuttings is that most end-users of hardwood lumber desire clear wood in their final product, whether it is flooring or furniture, so that it will machine smoothly and take finish or paint to be pleasing to the eye. But other users find the natural characteristics of the wood just as desirable to look upon as the clear area and, therefore, some grades specify “sound cuttings” which includes some of these natural features. Clear-face cuttings are used in the grades of FAS, FAS1F, Selects, No. 1 Common, No. 2A Common, and No. 3A Common (No. 2B and 3B Common grades require sound cuttings). NOTE: Season checks are considered ordinary when they can be surfaced off at standard surfaced thickness. In the example, both faces of a board are drawn. (Cuttings number 2 and 3 are clear-face cuttings. They each have a clear or defect free face on the poor side of the board and the reverse side is sound. Cutting number 1 cannot be

used as a clear-face cutting. Though it has a clear side on the poor side of the board, the reverse side contains wane, causing it to be unsound. To be a clear-face cutting, cutting number 1 would have to be re-measured so that no part of the wane would be on the reverse side. The reason the rules state that the cutting being measured must be on the “poor” side of the board goes along with the thought that a board is only as good as its poor face. However, the grades are flexible enough to allow other users, generally those using only one exposed face in the product, to specify certain grades determined from the better face and obtain price concessions over grades determined from the poor face.

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SOUND CUTTING “A cutting free from rot, pith, shake, and wane. Texture is not considered. It will admit sound knots, bird pecks, stain, streaks or their equivalent, season checks not materially impairing the strength of a cutting, pin, shot, and spot worm holes. Other holes 1/4” or larger are admitted but shall be limited as follows: One 1/4” in average diameter in each cutting of less than 12 units; two 1/4” or one 1/2” to each 12 units and on one side only of a cutting” (Paragraph 31).

Sound cuttings are used in the standard grades of No. 2B and No. 3B common and in the grades of species where it specifically states to use sound cuttings. Sound cuttings are usually the reverse side of clear cuttings, so absence of rot, pith, shake or wane is essential. The important thing to remember about the hole limitation is that it usually applies to equivalent defects, such as small, unsound knots or bark pockets, since the “hole” itself cannot extend through the board.

Both cuttings number 1 and number 2 are admitted as sound cuttings. The cuttings are from the poor side of the board, containing only sound defects, and their reverse sides are free of any unsound defects.

National Hardwood Lumber Association

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SURFACE MEASURE Surface measure (SM) is the measure of square feet on the face of a board. It is used for both grading purposes and for recording the amount of wood in each board. Though surface measure is commonly expressed simply as feet, it is actually a measurement of area in square feet.

To calculate the surface measure of a board, multiply the width of the board in inches and fractions of an inch times the length in whole feet (standard length) and divide the product by 12, rounding to the nearest whole number (SM’s are always expressed in whole feet). SM = Full width in inches and fractions of an inch x standard length 12 V (Rounding to the nearest whole foot) It is important to consider that surface measure as defined in the rules is only an approximation to the true surface area of a board, due to rounding after calculating. In a given load of lumber, rounding SM to whole numbers (some up and some down) averages out treating both buyers and sellers equally.

Surface Measure = Width “and fraction” x Length in whole feet 12

Surface Measure = 5 5/12 (less than 5 1/2 so round down)

Surface Measure = 6 1/2” x 10’ 12

Surface Measure = 5’

Surface Measure = 65 12

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Surface measure may also be found using a Lumber Rule (also called a Board Rule). Though many styles are available, most lumber rules are 3’ long and have either 6 or 8 scales running lengthwise on the ruler. The even length lumber (10’, 12’, 14’, 16’) is measured on one side and the odd length lumber (9’, 11’, 13’, 15’) is measured with the opposite side. To use the lumber rule the metal head is placed over one edge, and using the scale corresponding to the length of the lumber being measured, the ruler is “read” at the opposite edge of the board. This number, in feet, will be the surface measure of the board. For example, if this board were 9’ long, it would have a 4’ surface measure. A 16’ long piece would have an 8’ surface measure.

For measurements of 5’, 6’, 7’, and 8’ long lumber, use 1/2 of the reading given by the 10’, 12’, 14’, and 16’ scales respectively. Calculate the surface measure of the following boards:

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BOARD FEET “Random width lumber of standard grades and thicknesses shall be tallied surface measure and this tally shall be the number of feet, board measure, of 1” lumber. In lumber thicker than 1”, the tally so obtained is multiplied by the thickness as expressed in inches and fractions of an inch. Except squares, lumber less than 1” thick shall be counted surface measure” (Paragraph 18). SM x THICKNESS = BOARD FEET

CUTTING UNIT “The cutting unit is one inch by one foot (or its equivalent).” (Paragraph 37).

Cutting units are used to measure the amount of area that is contained in the cuttings of a board. To calculate the number of units in a cutting, multiply the width of the cutting in inches and fractions of an inch times the length in feet and fractions of feet. (The length of the cuttings must be converted to feet and fractions of feet; i.e. a cutting measure 3’ 6” long = 3 1/2 ft., a cutting measuring 2’ 4” long = 2 1/3 ft.). The cutting units for each cutting are then added together to get the total number of units available on a board.

Width in Inches + Fractions x Length in Feet + Fractions = Cutting Units Whenever a measurement expressed in inches is multiplied by a measurement expressed in feet, the answer obtained will be in cutting units.

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It is important to remember than when adding more than one cutting, the fractions must be kept. Quite often you will add another unit to your total cutting units.

Example: 10 3/4

=

9/12

18 1/2

=

6/12

12 1/3

=

4/12

40 19/12

=

41 7/12

NOTE: When your total cutting units are added, you must drop the fraction. Fractions in cutting units are never rounded up. The units are calculated for the cuttings used on the following board:

National Hardwood Lumber Association

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CUTTING UNIT WORKSHEET Calculate the number of units contained in the cuttings on the following board:

Answers:

17 17/16 units

30 15/16 units

V 18 2/3 units

National Hardwood Lumber Association

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STANDARD LENGTHS “The Standard Lengths for hardwood lumber are 4’, 5’, 6’, 7’, 8’, 9’, 10’, 11’, 12’, 13’, 14’, 15’, and 16’. ” (Paragraph 12). “Fractional lengths in the standard grades shall be measured as of the next lower standard length.” (Paragraph 16). Most grading rules for hardwood lumber are based on these standard lengths and any fractional length (or overlength) may be disregarded. The inspector is, however, permitted to use any part of the overlength to help establish the grade of the board. The standard length is used in computing the yield in clear cuttings required to establish the grade of a board. The hardwood industry has more opportunity to efficiently use all of the available material in a given tree compared to softwood lumber (logs). A softwood log 1’ short of a standard length must be cut back nearly 2 feet to the next category. A hardwood log (board) need only be cut back a maximum of just less than 1’ to reach the next category, and may in fact, be left overlength to allow the end user the advantage of using the overlength when the board is cut up. Today, most manufacturers double end trim lumber for ease of handling in mechanized sorters, and simply for appearance sake and to improve marketability.

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STANDARD ROUGH THICKNESS “Standard thicknesses for rough lumber are 3/8”, 1/2”, 5/8”, 3/4”, 1”, 1 1/4”, 1 1/2”, 1 3/4”, 2”, 2 1/4”, 2 1/2”, 3”, 3 1/2”, 4”, 4 1/2”, 5”, 5 1/2”, and 6”. One inch and thicker lumber may also be expressed in quarter inches as follows: (Paragraph 13)

1”

=

4/4

2”

=

8/4

4 1/2”

=

18/4

1 1/4”

=

5/4

2 1/2”

=

10/4

5”

=

20/4

1 1/2”

=

6/4

3”

=

12/4

5 1/2”

=

22/4

1 3/4”

=

7/4

3 1/2”

=

14/4

6”

=

24/4

4”

=

16/4

The thickness of a board is measured at the thinnest cutting used in establishing the grade. Since wood will shrink when drying, hardwood lumber is usually sawn at a “target thickness” that is thicker than the minimum requirement of the standard thickness desired. Specifying 4/4 lumber, for example, means that the usable portion (the cuttings) of any given board must be at least 1” thick. If, however, a sawmill produced 4/4 lumber that was exactly 1” thick with no over-thickness to allow for some shrinkage, many potential customers would have a difficult time using it. How much over-thickness is set as the “target” depends upon many factors including the species sawn, the amount of moisture in the log, and the ability of a particular sawmill to maintain uniformity in thickness (hold a tolerance). If a mill cannot hold a close tolerance, often a high “target thickness” is used to guarantee that most boards are at least 4/4 thick. This wastes some of the usable portion of the log. Some sawmills use a rule of thumb and saw 1/8” oversize, while others feel they hold a closer tolerance and saw 1/16” oversize for 4/4 lumber. In this example, 2 cuttings were used to establish a No. 1 Common grade. The thinnest cutting used is 1 1/2” thick, classifying the board as 6/4. The amount of thickness variation must then be measured and compared to the amount allowed by the Miscut Lumber Rule (see Paragraph 9).

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“Lumber shall be inspected and measured as the inspector finds it, of full length, width and thickness. No allowance shall be made for the purpose of raising the grade, except that in rough stock, wane and other defects which can be removed by surfacing to standard rough thickness shall not be considered.” (Paragraph 4). Any defect or portion of a defect located in the “overthickness” (the extra thickness that green lumber should have to allow for shrinkage when drying) may be disregarded. Defects may be admitted in the cuttings provided the portion of the defects taken will surface off to standard rough thickness.

The area of wane contained in the cutting would be removed if the board were to be surfaced to standard rough thickness (8/4 = 2”). A word of caution: A common phrase made by new inspectors is, “It will surface off. ” Don’t make this mistake! Paragraph 4 is intended to be applied on the odd piece that is virtually 1 or 2 cutting units short of making the grade and overthickness is present. If the thickness is 1/8” over the standard rough thickness, there are very few defects which will be removed in that 1/8”.

National Hardwood Lumber Association

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STANDARD SURFACED THICKNESS The Standard Surfaced Thickness estimates the finished thickness of products manufactured from lumber of standard rough thickness. This is used by inspectors to determine if certain features are to be considered. For example, stain on the surface of a board is not considered a defect if it does not penetrate below Standard Surfaced Thickness. Warp severe enough to prevent the entire board from surfacing two sides to Standard Surfaced Thickness also keeps it out of the FAS grade. Season checks are considered ‘ordinary’ if they will surface off at Standard Surfaced Thickness, and therefore, are permitted in a clear face cutting. If they go deeper, they are not considered ‘ordinary’ and are not admitted (Par. 22). The Standard Surfaced Thickness is found by subtracting 3/16” from the standard rough thickness in 6/4” and thinner stock and subtracting º” from the standard rough thickness in 7/4” and thicker stock. A chart showing the Standard Surfaced Thicknesses can be easily made as follows: Std. Rough

In

Std. Surfaced

Std. Rough

Thickness

Inches

Thickness

Thickness

In Inches

Std. Surfaced Thickness

3/4”

3/4” - 3/16” =

9/16”

7/4”

1 3/4” - 1/4” =

1 1/2”

4/4”

1” - 3/16” =

13/16”

8/4”

2” - 1/4” =

1 3/4”

5/4”

1 1/4” - 3/16” =

1 1/16”

10/4”

2 1/2” - 1/4” =

2 1/4”

6/4”

1 1/2” - 3/16” =

1 5/16”

12/4”

3” - 1/4” =

2 3/4”

In using the standard surfaced thickness, the inspector does not put every board through a planer. It is simply a guideline, which the inspector uses to make a decision. The Standard Surfaced Thickness limits are applied the same way in kiln-dried lumber as in green and air-dried stock.

MISCUT LUMBER RULE “Rough lumber shall be measured for thickness at the thinnest cutting used in establishing the grade. The cutting shall be of standard thickness with the exception that the percentage not included in the required cuttings may be scant in thickness, provided the cuttings are the full standard rough thickness and there is no greater variation in thickness than is shown in the chart describing miscut lumber. If there is a greater variation in thickness on the entire board than shown in the following table, the board shall be classed miscut” (Paragraph 9).

1/8”

in thicknesses of 1/2” or less

3/8”

in thicknesses of 2” to 3 1/2”

3/16”

in thicknesses of 5/8” and 3/4”

5/8”

in thicknesses of 4” to 6”

1/4”

in thicknesses of 4/4” to 7/4”

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The Miscut Lumber Rule is the guideline the inspector uses to determine whether a board has been properly sawn for thickness. First, the grade of the board must be determined. Then from the thinnest cutting used in establishing the grade, the thickness classification of the board is made. Based on the Standard Rough Thickness of the board, the amount of thickness variation allowed is determined using the chart for the Miscut Lumber Rule. The board is measured at its thinnest and thickest points on the entire board (regardless of the cutting placement) and the amount of thickness variation is calculated by subtracting the lesser thickness from the greater one. The amount of variation is compared to the amount allowed in the chart and a determination is made as to whether the board has been sawn within an acceptable tolerance. Miscut lumber is a problem for everyone involved. In practice, no inspector has time to measure each board for the thinnest and thickest points. In the sawmill, miscut boards waste potentially valuable material and reduce the yields possible from the logs. In the drying process they cause uneven piling in the stickered piles resulting in an increase in drying defects. And for the end users of hardwood lumber, problems can be expected when surfacing and machining miscut boards. It is, therefore, very important to recognize and maintain the proper thickness tolerance at every stage in the manufacturing process. On the following No. 1 Common board, two cuttings were used to establish the grade. The narrow cutting on the left is the thinnest of the two cuttings so the thickness of the board will be determined there. It measures 1” thick and would, therefore, be classed as a 4/4 board.

Using the chart for miscut lumber, up to 1/4” variation in thickness is allowed on boards 4/4” to 7/4” thickness between the thickest and the thinnest points of the board (not measuring over wane). The thinnest point in our example board is 1” and the thickest point is 1 3/8”. That is a difference of 3/8” which is greater than the 1/4” allowed. This board would then be reported as a 4/4 No. 1 Common MISCUT and would require remanufacturing before it could be shipped with a load of properly sawn 4/4 lumber.

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MINIMUM WIDTH RULE “Ninety percent of the minimum widths mentioned in all grades of lumber shall be full width; the remaining ten percent may be up to 1/4” scant in width. This rule also applies to each stock width and to any specified width except Sill Stock” (Paragraph 10). Most hardwood lumber is sawn on a random width basis, rather than by “stock” widths (for example 4”, 6”, 8”, and 10” wide, etc.) as in softwood lumber. Because of this an indefinite number of board widths may be found in a given load of hardwood lumber. Therefore, each grade of hardwood lumber specifies the narrowest width admitted in the grade. For example, the minimum width for an FAS board is 6”, for Selects it is 4” and for No. 1 Common it is 3”. The Minimum Width Rule is very useful in that it allows a 1/4” “forgiveness” on these ‘minimum width’ boards provided that not more than 10 percent of the number of minimum width boards included in a given load of lumber are narrower than the actual minimum width specified. This allows shipments of rough lumber to include an occasional 5 3/4” wide FAS, a 3 3/4” wide Selects and a 2 3/4” wide No. 1 Common Board. The Minimum Width Rule applies to all minimum widths specified in all grades. When defect limitations are based on the width of a board, the width requirements of the limitation are subject to the minimum width rule. For example, the minimum size for a board to be considered for Selects is 4”. Yet Selects has two other specified minimum widths, used in the application of wane limitations – one for 6” and wider boards, and another for the 4” and 5” wide boards. These are minimum widths mentioned in the grade of Selects and consequently are subject to the Minimum Width Rule. Occasional boards measuring 5 3/4” wide will be considered as 6” wide pieces and use the wane limitations for the 6” and wider pieces. Boards measuring 3 3/4” wide will not only be admitted in the Selects grade, but will use the wane limitations for the 4” and 5” wide pieces. NOTE: This rule is often misunderstood. For example: In a load of FAS lumber, 90 percent of the 6” wide boards must be a full 6” wide, 10 percent of the 6” wide boards may be 5 3/4”. In random width sawn lumber you should never have a problem with too many 5 3/4” wide boards.

DETERMINING THE WIDTH OF A BOARD

The width of this board is determined by its narrowest point in the standard length which is 5 3/4”. This board would be admitted into the grade of FAS as a 6” wide piece.

National Hardwood Lumber Association

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CHOOSING THE GRADING FACE “The grade shall be determined from the poor side of the piece, except when otherwise specified. In the cutting grades the poor side of the board is determined by the side with the lower grade, or if both sides have the same grade, it is the side with the least number of cutting units. When determining the poor side of a board, grade each face independently without regard to the reverse side of the cuttings. After the poor side has been determined, then look to the reverse side for soundness.� (Paragraph 5). Choosing the grading face is a very important step and the correct method should be thoroughly understood. First, each side of the board must be graded with NO REGARD for the opposite side. If different grades are achieved on opposite faces, the one with the lesser grade will be the poor face. If both faces have the same grade, the side with the least number units in the cuttings is the poor side. This example illustrates a board with different grades on its two faces. The lower side has a lesser grade and is the poor side of the board.

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CHOOSING THE GRADING FACE (continued) Again, the poor side is the one with the lesser grade.

If both faces have the same grade, the side with the least number of units is the poor side, whether the basic, extra or special yield was used. In the following example, both faces grade No. 1 Common. The upper face, having less units than the lower face, will be the poor side of the board.

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EFFECT OF UNSOUND DEFECTS ON REVERSE SIDE OF CUTTINGS

NOTE: Though both faces grade FAS, the grade of the board may not be FAS. The process described is used only to find the poor side of the board. Further steps are necessary to establish the board’s grade. Unsound defects, such as pith, which may not show on the surface, or unsound defects located on the reverse side of a cutting could change the grade of the board.

Although both sides grade No. 1 Common, side B is the poor side but as a result of the unsound knot on the reverse side, the 33 unit cutting would not be permitted. The grade of this board is No. 2A Common. National Hardwood Lumber Association

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TAPERING LUMBER “Tapering lumber in standard lengths shall be measured one-third the length of the piece from the narrow end for the surface measure” (Paragraph 17). Occasionally, boards are cut with one end wider than the other as shown in the example. These boards are measured for surface measure (and board feet) at a distance of 1/3 of the standard length measured up from the narrow end. Any overlength present is disregarded and the measurements are to be taken on the standard length of the board. The piece shown is a standard length (no overlength) board. The surface measure is taken at the point indicated which is one-third the length from the narrow end. The width of the board is still determined at the narrowest point of the standard length.

The surface measure of the above piece is 9’, but the board would be considered an 8” wide piece.

National Hardwood Lumber Association

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STANDARD GRADES The standard hardwood lumber grades are: CLEAR FACE CUTTINGS

SOUND CUTTINGS

FAS

No. 2B Common

FAS 1 FACE (F1F)

No. 3B Common

Selects

Sound Wormy

No. 1 Common

No. 2A Common

No. 3A Common

Each of the standard grades have minimum requirements that a board must meet before it can be assigned a grade. As stated in paragraph 6 under the General Instructions, “These rules define the poorest piece in any given Standard or Special grade, but the respective grades shall contain all pieces up to the next higher Standard or Special grade as defined in these rules.” The Standard Grades will apply to all lumber unless stated otherwise under the rules for Standard Inspection or Special Inspection or an exception is specifically stated in a contract and agreed to by both buyer and seller. The requirements to be discussed are as follows: minimum size board for each grade, the minimum size cuttings that must be used, the basic number of cuttings and the basic yield requirements, using the extra cuttings and extra yields, the special yields available, and the defect limitations as they apply to the respective grades. The standard hardwood lumber grades are: CLEAR FACE CUTTINGS

SOUND CUTTINGS

FAS

No. 2B Common

FAS 1 FACE (F1F)

No. 3B Common

Selects

Sound Wormy

No. 1 Common

No. 2A Common

No. 3A Common

Each of the standard grades have minimum requirements that a board must meet before it can be assigned a grade. As stated in paragraph 6 under the General Instructions, “These rules define the poorest piece in any given Standard or Special grade, but the respective grades shall contain all pieces up to the next higher Standard or Special grade as defined in these rules.” The Standard Grades will apply to all lumber unless stated otherwise under the rules for Standard Inspection or Special Inspection or an exception is specifically stated in a contract and agreed to by both buyer and seller. The requirements to be discussed are as follows: minimum size board for each grade, the minimum size cuttings that must be used, the basic number of cuttings and the basic yield requirements, using the extra cuttings and extra yields, the special yields available, and the defect limitations as they apply to the respective grades.

National Hardwood Lumber Association

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SUMMARY OF THE STANDARD GRADES — FAS Minimum Size Board

6” x 8’

SM for Extra Cutting

6’ to 15’ SM

Minimum Size Cuttings

4” x 5’ or 3” x 7’

Extra Yield

SM x 11 (91 2/3%)

Basic Yield

SM x 10 (83 1/3%)

Special Yield

97% Rule — SM x 11.64

Basic Cuttings

SM ¸ 4 (maximum of 4)

In FAS, the grade must be determined from the poor side of the board using clear face cuttings with the reverse side of the cuttings sound. In addition to these requirements, there are also 6 defect limitations that apply to FAS, each of which must be met before the FAS grade can be concluded.

SUMMARY OF THE SIX DEFECT LIMITATIONS FOR FAS 1. Pith (in inches) not to exceed SM (in feet).

4. First Lineal Foot Rule — to contain not over 25% unsound wood.

2. Wane — 1/2 length.

5. Knots and Holes — 1/3 SM except when within first lineal foot.

3. Splits — 2 x SM except 1 ft. and shorter.

6. Warp and Cup — entire board S2S to Standard Surfaced Thickness.

— May diverge up to 1” in one lineal foot, except when one foot and shorter.

SAMPLE FAS BOARDS NOTE: Cuttings are shown on the poor side of board with reverse side sound. The drawings on the next page show three methods of obtaining the grade of FAS in a piece containing 6’ SM. Board A. To grade FAS on this board under the Basic Yield, one cutting is permitted (SM ¸ 4 dropping fractions) to yield SM x 10 (60 cutting units). Board B. This piece would qualify for FAS under the Extra cutting (SM between 6’ to 15’ will permit one additional cutting). Extra Yield SM x 11 (66 cutting units).

NOTE: A  n inspector must remember that when an additional cutting is taken you MUST obtain the extra cutting units required.

Board C. “FAS Admits also, pieces 6” and wider of 6’ — 12’ SM that will yield 97% (11.64/12) in two clear-face cuttings of any length, full width of the board” (Paragraph 63).

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The 97% Rule was established to include into the FAS grade those boards which were virtually clear but have a small defect preventing the inspector from obtaining the minimum FAS cutting sizes. To correctly apply this rule, two crosscuts full width of the board must be taken. The length is not limited. In cutting units the SM is multiplied by 11.64. The 97% Rule can only be used on pieces 6” and wider with a 6’ — 12’ SM. This piece will qualify for FAS under Special Yield. The 97% Rule comes into play on 9’ — 12’ lumber where a knot is located near the middle of the board and the minimum size cuttings cannot be obtained. To yield 11.64/12 (97%) the board has to be virtually clear, with clean edges (remember, cuttings must be full width) and a big SM or lots of overlength. Since this is simply another yield for FAS, the others being 10/12 and 11/12, the 97% Rule can be used on the better face of F1F and Selects, and of course as a last resort, for the FAS grade. Finally, the 97% Rule can never be used on a board with a 4’ or 5’ SM.

National Hardwood Lumber Association

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FAS — PITH LIMITATION “No piece shall be admitted which contains pith, boxed or showing, exceeding in the aggregate in inches in length the surface measure in feet” (Paragraph 56). Simply stated, an FAS board allows 1” of pith for every 1’ of surface measure.

The entire length of pith contained in the standard length of the board must be included whether it is showing on a face or is boxed. If the pith is present in more than one area of the board, as is pictured, the length of each section must be added. If the amount of pith present exceeds the amount allowed by the limitation, it will cause the board to be put out of the FAS grade.

National Hardwood Lumber Association

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FAS WANE LIMITATION “Wane shall not exceed on either edge of the piece over one-half the length in the aggregate� (Paragraph 57). By dividing the length of the board by 2 the amount of wane permitted in length is obtained. All the lengths of wane along one edge must be added together and neither edge of the piece may have wane exceeding 1/2 of the standard length. BOTH EDGES of the board may have wane up to 1/2 of the standard length. Any wane that falls in the overlength is disregarded for this limitation.

Neither edge of the board has wane exceeding 1/2 length. This board would qualify for FAS.

In this example neither edge of the board has wane exceeding 1/2 its standard length. Although your cutting(s) may extend into the overlength, an inspector must be careful that the wane in the standard length does not exceed 1/2 its length. This board would qualify for FAS.

National Hardwood Lumber Association

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FAS SPLIT LIMITATION “Splits shall not exceed in the aggregate in inches in length twice the surface measure of the piece, except when one foot or shorter and covered by Paragraph 59” (Paragraph 58). Splits” = 2 x SM (except when 1 foot or shorter) To determine the amount of split allowed in FAS, multiply 2 x SM. If the answer is more than 12” (one foot), this is the amount of split allowed. If the answer is less than 12”, it is disregarded since FAS boards allow all splits measuring 1’ and shorter. In actuality, this limitation applies only to those splits measuring longer than 12”, any number of splits less than 12” long are disregarded by this limitation. When splits are present on both ends of a board, the longest single split from each end, of those measuring more than 12”, must be added together. If the total is more than is allowed by the limitation, remanufacturing would be required before the board could be graded FAS. If multiple splits measuring over 12” are present on only one end, just the longest single split is considered and the rest are disregarded. In both cases, splits measuring 12” or less are disregarded by this limitation. NOTE: Splits less than 12” are disregarded as far as the FAS split limitation is concerned, but they are still defects and cannot be included in the clear face cuttings to establish the grade.

National Hardwood Lumber Association

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“Splits may diverge up to 1” to the lineal foot except when one foot or shorter and covered by Paragraph 59” (see Paragraph 58). When splits diverge, it means that they are moving either closer to or farther from a given edge. To determine the amount of divergence allowed by this limitation, the length of the split in inches must be converted into feet and fractions of feet.

In the example two splits are shown, a 10 inch split which is shorter than 1 foot and disregarded by this limitation, and a 20 inch split which is the maximum length allowed on a board having a 10’ surface measure and must be considered. Divergence of a split is allowed up to 1” to the lineal foot in length of the split. The split is 20” long = 1 2/3’ so an amount of divergence not exceeding 1 2/3” would be allowed.

National Hardwood Lumber Association

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FAS FIRST LINEAL FOOT RULE “Within one lineal foot from the ends of the boards of standard lengths there must be 50% clear wood, and not less than 25% of sound wood in the aggregate.” (Paragraph 59). To apply this rule, 1’ is measured in from each end of the board of standard lengths (overlength is disregarded). Of the area contained in the first foot on each end, 50% must be obtainable in two clear pieces of any shape and another 25% must be sound wood. Making a total of 75% of the area within the first foot that must be considered. The remaining 25% may contain defects, sound or unsound. In the following example, the right end of the board will not meet the requirements of the First Lineal Foot Rule for FAS. The 50% clear area is easily obtained in only 1 piece, however, it is not possible to get another 25% of the area contained in that first foot in sound wood. This will prevent this face of the board from grading FAS, regardless of how many units are obtainable in the cuttings, without remanufacturing. The purpose of the rule is to ensure that excessive amounts of wane, stain, splits and other defects are trimmed off the ends.

FAS KNOT LIMITATION “The average diameter of any knot, or hole, shall not exceed in inches one-third the surface measure of the piece in feet, except when it lies entirely within the first lineal foot of a board and is covered by Paragraph 59” (Paragraph 60). Knot or hole = 1/3 surface measure To determine the size of a knot or hole allowed, simply divide the surface measure of the board by 3. The resulting answer will be the maximum number of inches allowed in average diameter of any single knot or hole. This rule does not place a limit on the number of knots allowed on a given board but does restrict the size of the largest ones. Any knot, hole, or portion of knots or holes located on the standard length must be considered.

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In this example the knot which is 3” in average diameter exceeds the limitation of 1/3 SM but the knot falls within the 1st Lineal Foot and is disregarded. This board would qualify for FAS.

The above board yields the required amount of cutting units for FAS. Having an 8’ SM the largest knot or hole permitted would be 2 2/3” in average diameter (SM ¸ 3). As seen in the example the knot is 4 inches in average diameter which exceeds the limitation of 1/3 the SM and does not fall within the 1st Lineal Foot. This piece would not be permitted in FAS even though the board yields enough clear face cutting units to grade FAS.

National Hardwood Lumber Association

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FINDING AVERAGE DIAMETER “To determine the average diameter of a knot or hole, add the maximum length and maximum width and divide by 2” (Paragraph 47).

FAS WARP AND CUP RULE “In the grades of Selects and Better, the entire board must be flat enough to surface two sides to standard surfaced thickness” (Paragraph 29). Using this limitation the entire board (of standard length) regardless of the cutting placement must be considered. The purpose of this rule is to ensure that the large cuttings required in the FAS grade are not only obtainable but also will be straight enough and flat enough for practical use. Excessively cupped, twisted, or bowed boards that are not flat enough to have both faces dressed if the board were to be surfaced to the standard surfaced thickness must be put down into the common grades. This does not mean that all FAS boards must be surfaced to check the warp and cup limitation. This limitation is simply a guideline to be used for making consistent decisions.

National Hardwood Lumber Association

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FAS ONE FACE “Shall grade not below FAS on the better face for the particular species, and not below No. 1 Common on the reverse side. The reverse side of the cuttings in both FAS and No. 1 Common are not required to be sound. Wane on the No. 1 Common side is limited to the following: the width of wane from both edges, when added together, cannot exceed 1/3 the total width of the piece. The total length of wane on either edge cannot exceed 1/2 the length” (Paragraph 64). F1F must grade FAS for the particular species on the good face. The grading requirements for this face will vary depending on the species being inspected. The species that use the standard rules, such as the oaks, also would use the standard rules for FAS on the good side of an F1F board. The species with exceptions to the standard grades would use those exceptions on the good face. For example, Number 1 and 2 White Maple allows pieces 4” and 5” wide to be admitted in the FAS grade provided they are clear, so an F1F White Maple board will also permit boards measuring 4” and 5” provided the FAS face is clear. The minimum size for an F1F board is the same as the minimum size FAS board of the same species. Also, F1F boards must grade No. 1 Common on the poor side.

FAS 1 FACE (F1F) Unlike the grades of FAS, No. 1 Common, No. 2A and 2B Common, No. 3A Common, and No. 3B Common where the grade is determined from the poor side of the board, the FAS 1 Face (F1F) grade is based on the grade of BOTH faces. This grade requires that FAS must be established on the better face for the particular species and the poor side must yield at least a No. 1 Common. FAS1F boards must grade FAS on the good face for the particular species and not less than No. 1 Common on the poor side.

Minimum size board

FAS size for particular species

Minimum size cuttings 4” x 5’ or 3” x 7’ Basic Yield

SM x 10 (83 1/3%)

Basic Cuttings

SM ¸ 4

SM for Extra Cutting

6’ to 15’ SM

Extra Yield

SM x 11 (91 2/3%)

Special Yield

SM x 11.64 (97%)

National Hardwood Lumber Association

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FAS1F — WANE LIMITATIONS Once the FAS face and the No. 1 Common faces have been established (the reverse side of the cuttings are not required to be sound), the limitations must be checked. On the FAS face, all six of the standard FAS limitations will apply. The No. 1 Common face may have pith up to 1/2 the length of the piece (as described in the standard grade of No. 1 Common) and may have wane not exceeding 1/3 width by 1/2 length in the aggregate. FAS face — 1/2 length No. 1 Common face — 1/3 width by 1/2 length The width of wane may be on one edge of the board or that amount (1/3 x width) may be divided, showing on both edges of the board. When measuring the width of wane, the widest point of wane from each edge are added together. The length of wane allowed (1/2 x Length) may be on one edge or both edges. All the lengths of wane along one edge are added and may not exceed 1/2 the length and all the lengths from the opposite edge are added, and again, may not exceed 1/2 the length. The lengths of wane are not added from one edge to the other. Any wane in the overlength may be disregarded. When grading F1F boards, both faces must be graded independently from one another. The reverse side of the clear-face cutting(s) used to establish the FAS grade on the better face and No. 1 Common grade on the poor side are NOT!! required to be sound.

Widest wane from opposite edges is added together and may not exceed 1/3 width (8 1/4” x 1/3 = 2 3/4” maximum width of wane permitted). In the above example, both faces yield enough cutting units to obtain the respective grades required on each face but the wane exceeds the 1/3 width limitation on the No. 1 Common side and the piece would not be permitted as an F1F. The wane limitation of 1/2 length applies in the same manner as it does for the FAS face. (See Six Defect Limitations for FAS pages 16-17).

National Hardwood Lumber Association

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SUMMARY OF THE STANDARD GRADES — SELECTS

Minimum Size Board

4” x 6’

Minimum Size Cuttings

4” x 5’ or 3” x 7’

Basic Yield

SM x 10 (83 1/3%)

Basic Cuttings

SM ¸ 4

SM for Extra Cutting

6’ to 15’ SM

Extra Yield

SM x 11 (91 2/3%)

Special Yields

97% Rule — SM x 11.64 and 2’ and 3’SM

must yield 100% clear or SM x 11 in one cutting.

Unlike the grades of FAS, No. 1 Common, No. 2A and 2B Common, No. 3A Common, and No. 3B Common where the grade is determined from the poor side of the board, the Selects grade is based on the grade of both faces. The grade of FAS must be established on the good face and No. 1 Common on the poor face.

SELECTS — FAS FACE “SELECTS admits: Pieces of 2’ and 3’ surface measure that will yield 100% or 11/12 (91 2/3%) clear in one cutting on the better face with the reverse side of the board grading not below No. 1 Common. Will also admit pieces of 4’ and over surface measure that will grade FAS on the better face with the reverse side of the board grading not below No. 1 Common. The reverse side of the cuttings in both FAS and No. 1 Common are not required to be sound.” (Paragraph 68).

National Hardwood Lumber Association

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SELECTS Selects admits pieces that will grade FAS on one face with the reverse side of the board grading not below No. 1 Common. When grading Selects, both faces must be graded independently from one another. The reverse side of the clear face cuttings used to establish the FAS and No. 1 Com are not required to be sound.

In addition to the number of cutting and yield requirements, Selects also imposes wane limitations that may apply to either or both faces of the board.

National Hardwood Lumber Association

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SELECTS — 4” AND 5” WANE LIMITATIONS “In pieces 4” and 5” wide, wane on either face is limited to the following: the width of wane from both edges, when added together, cannot exceed 1/3 the total width of the piece. The total length of wane on both edges, when added together, cannot exceed 1/2 the length” (Paragraph 69). There are two sets of wane limitations used in the grade of Selects. A set for the boards measuring 6” and wider and a set for the boards measuring only 4” and 5” wide. The 4” and 5” wide rules allow an amount of wane on one edge not exceeding 1/3 the width of the board and not more than 1/2 of the standard length. If the wane is present on both edges of the board, the amount allowed by the limitation may be broken up and shown on both edges. In applying this rule, the widest point of wane from one edge is added to the widest point of wane from the opposite edge and the length(s) of wane along one edge is added to the length(s) of wane along the opposite edge. (This is the only time in the standard grades that the length of wane is added from edge to edge.) 1/3 width x 1/2 length NOTE: The wane limitation for these narrow Selects applies to both sides of the piece.

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To determine the total amount of wane present, add the widest point of wane from one edge to the widest point of wane from the opposite edge and add all the lengths of wane along one edge to all the lengths of wane from the opposite edge. These totals should be compared with the amount allowed by the limitations.

This board CANNOT be graded Selects because the amount of wane present on the board exceeds the amount of wane allowed by the limitation. Using the 4� and 5� wane limitations the widest point of wane from one edge is added to the widest point of wane from the opposite edge and all the lengths of wane from BOTH edges are added.

National Hardwood Lumber Association

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SELECTS — 6” AND WIDER WANE LIMITATIONS “In pieces 6” and wider, wane on the No. 1 Common side is limited to the following: the width of wane from both edges, when added together, cannon exceed 1/3 the total width of the piece. The total length of wane on either edge cannot exceed 1/2 the length.” (Paragraph 68). No. 1 Common side — 1/3 width by 1/2 length The wane limitations for Selects boards measuring 6” and wider are somewhat different than those used for the 4” and 5” wide Selects boards. The limitations described in the rule above apply to the No. 1 Common side of Selects measuring 6” and wider only. The FAS face of all 6” and wider Selects boards are governed by the standard FAS limitation of 1/2 the length. In applying these wane limitations the widest point of wane from one edge is added to the widest point of wane from the opposite edge and either or both edges may have wane up to the full amount allowed by this limitation. NOTE: The Minimum Width rule, paragraph 10 of the General Instructions, will apply to the 6” and wider wane limitations for Selects since 6” is a minimum width mentioned in this grade allowing a Common back Selects measuring 5 3/4” wide to use the 6” and wider rules.

National Hardwood Lumber Association

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SUMMARY OF WANE LIMITATIONS

FAS

-

1/2 length

F1F

FAS face

-

1/2 length

1 Com face

-

1/3 width by 1/2 length

Length of wane may be on both edges.

Selects 6” & wider

FAS face

-

1/2 length

1 Com face

-

1/3 width x 1/2 length

Selects 4” & 5”

FAS face

-

1/3 width by 1/2 length

1 Com face

-

1/3 width by 1/2 length

Length of wane must be added from both edges.

NOTE: The wane limitation of 1/3 width will be applied in the same manner in the grades F1F, Selects 6” and wider, 4” and 5” Selects.

SUMMARY OF THE STANDARD GRADES — NO. 1 COMMON

Minimum Size Board

3” x 4’

T

Basic Cuttings

(SM + 1) ¸ 3

Minimum Size Cuttings

4” x 2’ or 3” x 3’

Extra Yield

SM x 9 (75%)

Basic Yield

SM x 8 (66 2/3%)

Special Yields

1’ SM must be 100% clear

2’ SM must yield SM x 9

No. 1 Common boards are graded from the poor side using clear face cuttings with the reverse side of the cuttings sound.

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SPECIAL YIELDS — NO. 1 COMMON The special yields for No. 1 Common are:

SAMPLE NO. 1 COMMON BOARDS Board A. This board has a 4’ SM. To grade this piece for a No. 1 Common, you must yield 32 cutting units (SM x 8) in one cutting (SM + 1 ÷ 3 dropping fractions). Board B. This board also has a 4’ SM. Because two cuttings have been used to establish this board as a No. 1 Common, the Extra cutting (SM between 3’ to 10’ will permit one additional cutting) and Extra yield (SM x 9) will apply. Both boards yield sufficient cutting units to grade No. 1 Common.

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NO. 1 COMMON — PITH LIMITATION “No piece shall be admitted which contains pith boxed or showing, exceeding in the aggregate one-half its length” (Paragraph 72).

The pith limitation is the only defect limitation that applies to the No. 1 Common grade. An unlimited amount of wane, splits, knots, bark pockets and any other defects are allowed on the boards provided the required yield in clear area is established. NOTE: Pith, either boxed or showing, must be outside of the No. 1 Common cuttings.

SUMMARY OF THE STANDARD GRADES — NO. 2A AND NO. 2B COMMON

Minimum Size Board

3” x 4’

SM for Extra Cutting

2’ SM to 7’ SM

Minimum Size Cutting

3” x 2’

Extra Yield

SM x 8 (66 2/3%)

Basic Yield

SM x 6 (50%)

Special Yield

1’ SM must yield SM x 8

Basic Cuttings

SM ¸ 2

The grade of No. 2 Common is divided into two categories: No. 2A Common which is established using clear face cuttings and No. 2B Common which requires the cuttings only be sound. All other No. 2 Common grade requirements apply to both No. 2A and 2B. If clear face cuttings are needed, specify No. 2A Common. NOTE: “No. 2A Common and No. 2B Common may be combined as one grade, No. 2 Common, and when so combined and specified should be understood to include all the No. 2A Common that the logs produce” (Paragraph 51).

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SAMPLE NO. 2A COMMON

The above board has a 5’ SM. To grade as a No. 2A Common, 30 cutting units (SM x 6) are required in two cuttings (SM ¸ 2 dropping fractions). NOTE: Cuttings are shown on the poor face of piece. The reverse of all cuttings are sound.

SPECIAL YIELDS — NO. 2A & 2B COMMON 1’ surface measure must yield SM x 8 in one cutting (66 2/3%)

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SAMPLE NO. 2B COMMON

NOTE: Cuttings are shown on the poor face of piece. The reverse of all cuttings are sound.

SUMMARY OF THE STANDARD GRADES — NO. 3A COMMON

Minimum Size Board

3” x 4’

Basic Yield

SM x 4 (33 1/3%)

Minimum Size Cutting

3” x 2”

Extra Yield

Does not apply

Special Yield

Must grade at least No. 2A Common on the BETTER face

(Unlimited number of cuttings are allowed) Extra Cutting

Does not apply

with the reverse side of the cuttings sound.

A board may be graded No. 3A Common using either one of two options. The first option is to grade the board from the poor side using clear face cuttings with the reverse side of the cuttings sound, if the number of cutting units in the cuttings meet the requirements of the No. 3A Common. The second option is to grade the board from the BETTER face establishing at least a No. 2A Common grade using all of the standard rules for No. 2A Common with the reverse side of the cuttings sound. No. 3A Common has no limitations on defects provided the required yields as described by the grading rules are satisfied.

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SUMMARY OF THE STANDARD GRADES — NO. 3B COMMON

Minimum Size Board

3” x 4’

Basic Yield

SM x 3 (25%)

Minimum Size Cutting

Not less than 1 1/2” wide containing not less

Extra Yield

Does not apply

than 36 square inches in SOUND CUTTINGS.

Special Yield

Does not apply

Does not apply

Extra Cutting

No. 3B Common boards are graded from their poor side using SOUND CUTTINGS with the reverse side of the cuttings sound. There are no additional defect limitations for the grade of No. 3B Common. Since this is the lowest of the standard grades, any boards that do meet the minimum requirement for No. 3B Common are tallied as “below grade.”

STANDARD KILN DRIED RULE Thus far, all of the grading rules discussed have been for green and air dried lumber. Once the lumber has been placed in the kiln and dried thoroughly, some additional grading rules apply. Kiln dried lumber is inspected under the Standard Kiln Dried Rules. This set of rules is normally used on kiln-dried lumber unless specified in the contract for sale of the lumber. “Kiln dried lumber will be graded and measured as such, the grading rules for air dried lumber to be applied in all respects, unless otherwise specified. Rough kiln dried lumber specified 3/8” to 1 3/4” thick may be 1/16” scant of the nominal thickness; 2” and thicker may be 1/8” scant and the 10% of scant quartered lumber admitted by Paragraph 36 may be 3/32” scant on one edge to 1” to 1 1/2” lumber and 3/16” on one edge in 2” and thicker. The minimum widths mentioned in all grades may be 1/4” scant in width and the 10% admitted by Paragraph 10 may be 1/2” scant in width. In other respects the rules for grading air dried lumber shall apply.” (Page 58, Rule Book, 2007 Edition). National Inspectors will mark certificates under these specifications “Standard Kiln Dried Rule Applied.”

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INSPECTION OF KILN DRIED LUMBER MEASUREMENT AFTER KILN DRYING “Sales of random width hardwood lumber measured after kiln drying shall be quoted, invoiced, and delivered on the basis of net board footage, with no addition of footage for kiln drying shrinkage or surfacing.” When inspecting kiln dried lumber, National Inspectors will make no addition for estimated kiln shrinkage. In contracts for kiln dried lumber, the Standard Kiln Dried Rule shall apply unless otherwise specified in the sales contract. NOTE: These guidelines were adopted by the National Conference of Weights and Measures on July 21, 1977 and compiled as Uniform Laws and Regulations. These Uniform Laws and Regulations are used by most states and other political subdivisions when adopting official laws and regulations in their jurisdiction. You are advised to consult legal counsel in your local jurisdiction if you wish to use a different measuring procedure for sales of hardwood lumber.

MEASUREMENT BEFORE KILN DRYING “Sales of hardwood lumber measured and sold prior to kiln drying or surfacing shall be quoted, invoiced, and delivered on the basis of net board footage before kiln drying or surfacing. If the lumber is to be kiln dried or surfaced at the request of the purchaser, the kiln drying or surfacing charge shall be clearly shown and identified on the quotation and invoice.” NOTE: These guidelines were adopted by the National Conference of Weights and Measures on July 21, 1977 and compiled as Uniform Laws and Regulations. These Uniform Laws and Regulations are used by most states and other political subdivisions when adopting official laws and regulations in their jurisdiction. You are advised to consult legal counsel in your local jurisdiction if you wish to use a different measuring procedure for sales of hardwood lumber.

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HARDWOOD LUMBER GRADES STANDARD INSPECTION

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INDEX Board Feet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Selects — 4” and 5” Wane Limitation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Choosing the Grading Face. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Selects — 6” and Wider Wane Limitations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Clear-Face Cuttings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Selects — FAS Face. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Cutting Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Sound Cutting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Cutting Unit Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Special Yields — No. 1 Common. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Cuttings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Special Yields — No. 2A & 2B Common. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Determining the Width of a Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Standard Grades. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Development of Hardwood Lumber Grades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Standard Kiln Dried Rule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Effect of Unsound Defects on Reverse Side of Cuttings . . . . . . . . . . . . . . . . . . . 22

Standard Lengths. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

General Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Standard Rough Thickness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

FAS First Lineal Foot Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Standard Surfaced Thickness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

FAS Knot Limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Summary of Standard Grades. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

FAS One Face . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Summary of the Six Defect Limitations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

FAS 1 FACE (FIF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Summary of the Standard Grades — No. 1 Common. . . . . . . . . . . . . . . . . . . . . . . . . 41

FAS1F — Wane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Summary of the Standard Grades — No. 2A and No. 2B Common. . . . . . . . . . . . . 43

FAS — Pith Limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Summary of Standard Grades — No. 3A Common. . . . . . . . . . . . . . . . . . . . . . . . . . 45

FAS Split Limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Summary of Standard Grades — No. 3B Common. . . . . . . . . . . . . . . . . . . . . . . . . . 46

FAS Wane Limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Summary of the Standard Grades — Selects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

FAS Warp and Cup Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Summary of Wane Limitations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Finding Average Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Surface Measure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Hardwood Lumber Grades Standard Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Tapering Lumber. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

How Boards Are Graded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Inspection of Kiln Dried Lumber Measurement After Kiln Drying . . . . . . . . . . . . . . 47 Measurement Before Kiln Drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Minimum Width Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Miscut Lumber Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 No. 1 Common — Pith Limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Sample FAS Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Sample No. 1 Common Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Sample No. 2A Common . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Sample No. 2B Common . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Selects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

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NHLA is a member of AHEC.

National Hardwood Lumber Association PO Box 34518 | Memphis, TN 38184-0518 | 901-377-1818 | 901-382-6419 (F) www.nhla.com National Hardwood Lumber Association

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Lumber Grading Training Manual 2008