Clamping piece and external member for sample stretching and tensile testing machine

The utility model provides a clamping piece for sample stretching, a sleeve piece and a tensile testing machine, and belongs to the technical field of material testing, the clamping piece is used for connecting a sample of the tensile testing machine, a clamp seat of the tensile testing machine is connected with a clamping seat of the sample, the clamping seat is provided with a first clamping groove for clamping the end of the sample, and the clamping groove is provided with a second clamping groove for clamping the end of the sample. The clamping piece comprises a limiting part and a clamping part, the limiting part is used for being clamped in the first clamping groove and restraining the relative position between the clamping piece and the clamping seat in the stretching direction of the sample, and a second clamping groove used for clamping the end of the sample is formed in the clamping part. According to the utility model, the clamping problem of test pieces with different specifications in the tensile