1. For general metal and non-metal samples, the jaws of the fixture are directly in contact with the sample. Generally, high-quality alloy structural steel, alloy high carbon steel, cold work die steel, etc. are used, and the strength is increased by a suitable heat treatment process. Abrasion resistance. Sometimes special steel is also mounted at the jaws, or gold steel sand is applied to the surface of the jaws.

2. For some small test force fixtures, the surface in contact with the sample is made of soft rubber.

3, The clip is generally made of high-quality medium carbon steel, alloy structural steel, through the appropriate heat treatment process to increase its mechanical properties. In order to reduce the weight, non-ferrous metals such as aluminum alloys and special metals are sometimes used. Cast structures are also sometimes used.