SATEC™ SERIES IN-HEAD GRIPS FOR ROUND SPECIMENS

Designed as an integral part of the testing platform, vee-wedge jaws fit directly into the crosshead pocket of the frame and provide a grip adaptable to a variety of testing applications. These jaws are made from rugged heat-treated steel, and are ideal for testing a variety of round specimens. Most of the offered vee-wedge jaws can also be produced using through-hardened tool steel, which is suitable for rebar applications. The teeth of the jaws are also hardened, and different tooth options increase the application range. A coarse tooth pattern is best for softer materials and higher loads, whereas a finer tooth pattern is best for harder materials. The wedge design causes the gripping force to increase as tensile force is applied. This ensures a secure gripping action, which decreases occurrences of slippage throughout the range of the test.

Filler plates are provided with the purchase of testing frames, and allow a variety of specimen thicknesses to be tested. The variety of available jaws also allows variability in the range of specimen diameters. This versatility is due to the different depths and angles of the vee-notch in the jaws available, depending on the specific dimensions of the specimen being tested.

Principle of Operation

A pair of wedge grip jaws are used in each crosshead pocket to grip the upper and lower end of the specimen. The grip jaw pairs are actuated (opened and closed) by one of two basic methods: pinion or lever arm. When pinion actuation is used, the back surface of each grip jaw is equipped with rack teeth to facilitate actuation of the jaws in the crosshead pocket. A pinion meshes with these rack teeth and, as the pinion is actuated by the operator either manually or hydraulically, the jaws are raised or lowered in the crosshead pocket. When lever arm actuation is used, a grip hanger is attached to each grip jaw. Once the jaws are installed in the grip pocket, the grip hangers will pivot about a lever arm. As the operator actuates the lever arm, the jaws are raised or lowered in the crosshead pocket. Once the specimen has been inserted between the jaws, the operator applies an initial clamping force to the specimen. When the test is begun, the wedge design of the grip jaws and pocket translates some of the tensile force applied by the load frame into a gripping force on the specimen. As the tensile force increases so does the gripping force, reducing instances of specimen slippage.

Application Range

• Jaws are rated to full machine capacity — up to 3,000 kN (600,000 lbf; 300,000 kgf)

• Suitable for use with a variety of round specimens (including pipe, bar, tube and rebar) made of a variety of materials

• (including steel, wrought iron, copper, bronze, brass, aluminum, and composites)