Auxiliary clamp for hardness test

The utility model provides an auxiliary clamp for a hardness test, which is capable of stably clamping samples with various shapes, and conveniently regulating a to-be-tested surface to a horizontal position and ensuring no displacement during test. The auxiliary clamp comprises a base and a rotating device arranged on the base, wherein prominent supporting lugs are respectively processed on the two sides of the base, two lug axle holes are formed on the supporting lugs, and are coaxial and horizontal; the rotating device comprises a semi-circular copper axle sleeve, through holes communicated with the lugs axle holes are formed on the two sides of the copper axle sleeve, a semi-circular clamp body is embedded in the copper axle sleeve, and the clamp body and the copper axle sleeve are clamped together between the lug axle holes through locknuts, and can rotate around the lugs axle holes; and a square sliding groove is processed on the clamp body along the vertical axis direction, and an adjustable clamp is arranged in the sliding groove. The auxiliary clamp has a simple structure and low cost, solves the clamping problem of the samples with various shapes, and can conveniently regulate the to-be-tested surface to the horizontal position.