Standard Tensile Wedge Grips
Fig. 1: Pair of 30,000 lb. capacity Standard Tensile Wedge Grips with 3 in. wide grip faces, 2.25 in. grip length, Brand type Dm end fittings.
There are two basic types of mechanical wedge grips. Either the grip bodies move and the wedges remain stationary while being tightened on the specimen, or the wedges move as they tighten on the specimen and the bodies of the grips remain stationary. The former are termed “standard grips” and the latter are termed "simple grips".
Because the wedges in the “standard” wedge grips do not move axially relative to the specimen during clamping, the grips do not have the potential of putting the tensile specimen in compression, possibly damaging it as the grips are tightened. This is obviously a more desirable condition, in general. However, the Simple Tensile Wedge Grips are shorter in overall length (and thus better able to fit into confined spaces), and are slightly easier to fabricate and thus are slightly less expensive.
Fig. 1 shows a pair of standard 30,000 lb. capacity and 2 in. wide tensile wedge grips, representing one of the many load capacities and specimen widths available.
Fig. 2 shows a pair of grips of the same 30,000 lb. capacity, but with 1 in. wide grip faces. The grip bodies are correspondingly only 1 in. wide, resulting in them being wider and taller to accommodate the induced stresses when loaded.
Fig. 2: Pair of 30,000 lb. capacity Standard Tensile Wedge Grips, 1 in. wide grip faces, 2.25 in. grip length, Brand type Dm end fittings.
For comparison, Fig. 3 shows a 2 in. wide wedge grip, rated for only 10,000 lb. capacity. Note the more compact grip body relative to the higher load capacity grips shown in Fig. 2. Additionally, the end connection is a male thread, with lock ring. The wedge grip inserts have diamond serrations.
Fig. 3: 10,000 lb. capacity Standard Tensile Wedge Grips, 2 in. wide grip faces, 2.25 in. grip length, male thread end fittings.
