The GD751-240k meets the sample gripping requirements of ASTM D751. The breaking strength of coated plastics is determined using the grab test method. Per ASTM D751, clamps for holding a coated fabric specimen must have smooth, flat, and parallel metallic gripping surfaces to avoid slippage. The dimension of all gripping surfaces parallel to the direction of application of the load must be 25 mm (1 in.); the dimension perpendicular to this direction shall be 1 inch for the face jaw and 50 mm (2 in.) or more for the other. All edges that might cause a cutting action shall be rounded to a radius of not over 0.4 mm (1?64 in.). The design of the clamp shall be such that one gripping surface shall be an integral part of the rigid frame of the clamp while the other shall be on a part hinged or swiveled to the movable member of the clamp. The distance between the clamps at the start of the test shall be 75 mm (3 in.). Reference ASTM Standard D 751, 2002, Standard Test Methods for Coated Fabrics, Copyright ASTM International, West Conshohocken, PA, 2007.