THE MAINTENANCE CONNECTION, INC. Anchors
Screw & Bolt Anchors The information on the following pages is designed to be used as a reference in selecting anchors and fasteners. It is intended to provide the user with practical information for the most common applications. It is not possible to include information on all applications and data for all construction materials. It is the responsibility of the user to verify the accuracy of the text and the data contained in this handbook as it pertains to each unique application.
Selection and Specification of Anchors Until the beginning of this century, an anchor was a piece of wood or a plug of lead carved to size and wedged into a hole, into which a nail or screw was driven. These early anchors were then followed by lead and fiber anchors with hollow cores which were mass produced in a variety of sizes to match hole sizes and screw sizes. A multitude of anchor types have been developed in subsequent years leading to today’s proliferation of choices. But while this variety of choices does provide a better match up of anchors to specific needs, it also makes the selection process that much more difficult. For that reason, before selecting the type, size and number of anchors to be used for any given application, all of the following factors should be taken into consideration.
Base Material The strength of the masonry material is a key factor in selecting an anchor. Maximum anchor performance requires that the material in which the anchor is installed can also sustain the load to which the anchor will be subjected. Anchors installed in stone and dense concrete can withstand far greater “pullout loads” than the same anchor installed in lightweight concrete, block or brick. Medium-heavy to heavy loads cannot be safely installed in soft materials such as stucco, grout, plaster or plasterboard. Materials should be fully cured prior to anchor installation. The length, width, and thickness of the base material should be considered. Normally, the width should be at least twice the recommended edge distance. The depth of anchor embedment should not exceed 80% of the base material thickness.
A N C H O R S
Material Composition of Anchors The Maintenance Connection offers a selection of anchors to meet the requirements of most applications. When reviewing the basic considerations for selection of an anchor, the material from which the anchor is manufactured should be considered. Anchors selected should be manufactured from a material which is suitable for their intended use. For example, anchors manufactured from a material with a melting point of less than 1000° F. are not normally recommended for overhead applications. Examples of these materials would include zinc (Zamac), lead, plastic and adhesives. Consideration should also be given to the strength of the anchor material in relation to the applied loads, including bending. The bolts used in conjunction with an anchor should be capable of sustaining the applied loads. Information on this and the following pages obtained from Rawl Catalog #0013 ©1989 The Rawlplug Company, Inc.
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