6.2 Clamps, having all gripping surfaces parallel, flat, and capable of preventing slipping of the specimen during a test. Each clamp shall have one jaw face measuring 25.4 by 50.8mm, with the longer dimension parallel to the direction of application of the load. The other jaw face of each clamp shall be at least as large as its mate. Each jaw face shall be in line, both with respect to its mate in the same clamp and to the corresponding jaw of the other clamp.