How does the tensile test always breaks at the root of the jaw？

When the electronic tensile universal testing machine is used for the tensile test, the sample is always broken at the root of the jaw.

1. The coaxiality of the electronic universal testing machine may be too large, and the sample is in a vertical state from time to time during the tensile test. The error of the experimental force value is also large.

2. If the specification is not standardized when clamping the tensile specimen, refer to the clamping method of the drawing.

   
   

3. The size of the selected jaw is not suitable. Select the appropriate jaw according to the size of the sample during the test. Remember not to use the flat jaw to hold the round specimen.

   
   

Note that some electronic tensile universal testing machines may use pneumatic clamps or hydraulic clamps for the purpose of improving the grade. Also pay attention to the use. Not all materials can be used, and the fixtures suitable for the specimens can be used.