MECHANICAL WEDGE GRIPS FOR FATIGUE TESTING Instron® mechanical 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 grip is designed to allow test specimens to be securely gripped without introducing axial pre-loading to the specimen. This is achieved by using jaw faces that move in a horizontal direction relative to the specimen.
Principle of Operation 2.7
General Purpose Fatigue Grips
Each grip is mechanically operated, with gripping force being applied via movement of the grip body relative to the wedge-shaped jaw faces. This movement is induced by the tightening of four socket cap screws on the underside of the grip head. Each jaw face is located in the grip body by two extension springs, which allow the jaw faces to release the specimen after testing. The grip body wedge area is fitted with jaw guides, to ensure that the jaw faces remain square to each other and to the specimen.
Application Range
Safety Advice
• 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
Review safety note on page 234
MECHANICAL WEDGE GRIPS Catalog Number
2743-402
Upper Effective Length
Accessory Width
Accessory Height
Accessory Weight
mm
in
mm
in
mm
in
kg
lb
°C
°F
M30 × 2 RH M30 × 2 RH 170 (Type If) (Type If)
6.9
172
6.77
170
6.9
26
57.3
-70 to +300
-94 to +572
Upper Fitting
Capacity kN
kgf
lbf
±100
±10,000
±22,500
Lower Fitting
ITEMS FOR USE WITH 2743-402 Catalog Number
Description
2704-521
Jaw faces for flats (flat-serrated, 0 - 7.8 mm) 50 mm wide
2704-522
Jaw faces for flats (flat-serrated, 7.1 - 15.7 mm) 50 mm wide
141
2704-529
Jaw faces for flats (flat-serrated, 15.0 - 21.0 mm) 50 mm wide. Quantity: 4 faces
2704-527
Jaw faces for flats (flat-serrated, 16.5 - 25.2 mm) 50 mm wide. Quantity: 4 faces
2704-525
Jaw faces for flats (carbide-coated, 0 - 7.8 mm) 50 mm wide
2704-526
Jaw faces for flats (carbide-coated, 7.1 - 15.7 mm) 50 mm wide
2704-523
Jaw faces for rounds (V-serrated, 6.1 - 11.9 mm)
2704-524
Jaw faces for rounds (V-serrated, 9.9 - 16.0 mm)
2704-528
Jaw faces for rounds (V-serrated, 16.0 - 20.0 mm) 50 mm wide. Quantity: 4 faces
2704-530
Accessory mounting block to provide M30 × 2 RH female thread. Set of 2 blocks
Temperature Range
Static or Fatigue Rated
Fatigue
