HYDRAULIC WEDGE GRIPS FOR FATIGUE TESTING
2.7
1
2
3
4
General Purpose Fatigue Grips
Instron® hydraulic wedge action grips may be used in static or dynamic materials testing applications. Interchangeable wedge-shape grip faces accommodate either flat or round specimens. The grips maintain a constant gripping force on the specimen regardless of the test forces acting upon it, as long as there is hydraulic pressure to the grips.
Principle of Operation Each grip functions independently of the other, with an external hydraulic supply providing pressure to both open and close the grips. When gripping pressure is applied, the relative vertical position of the specimen / jaw faces remains unchanged to prevent specimen load generation during the gripping process. Once the grip faces contact the specimen, the hydraulic pressure produces a vertical force on the grip head. The grip force will remain constant as the design automatically compensates for specimen thickness changes.
Application Range • Type of loading: Static or dynamic, reverse stress • Specimen material: Metallics, plastics, composites • Specimen geometries: Round section (not buttonhead) or flat specimens with or without shoulder tab
Safety Advice Review safety note on page 234 HYDRAULIC WEDGE GRIPS Catalog Number
Upper and Lower Fittings
Capacity kN
kgf
lbf
Accessory Width
Accessory Height
Accessory Weight
Temperature Range
mm
in
mm
in
kg
lb
°C
°F
Static or Fatigue Rated
1
2742-301
±30
±3,000
±6,800
M30 × 2 RH (Type If)
125
4.92
187
7.36
9
20
+4 to +65
+39 to +150
Fatigue
2
2743-401
±100
±10,000
±22,000
M30 × 2 RH (Type If)
200
7.87
219
8.62
31
68
+4 to +65
+39 to +150
Fatigue
3
2742-501
±250
±25,000
±56,000
M48 × 2 RH (Type Ilf)
320
12.6
311
12.25
100
220
+4 to +65
+39 to +150
Fatigue
4
2742-601
±500
±50,000
±110,000
M72 × 3 RH (Type IIIf)
400
15.75
360
14.17
255
561
+4 to +65
+39 to +150
Fatigue
139
