A procedure and experimental equipment are developed to perform small punch testing of miniature disk specimens. The procedure is experimentally tested on specimens of 45 steel. A comparative analysis is made of the known procedures for determining the yield stress from the small punch load-displacement curves for miniature disk specimens.Keywords: small punch testing of miniature disk specimens, stress-strain curve, yield stress. Introduction.The method of small punch testing of miniature disk specimens, known as small punch test (SP-test), is based on the recording of the ball punch deformation of a miniature disk specimen (SP disk microspecimen) rigidly fixed along the perimeter in a special device in the coordinates of the load applied to the ball vs depth of punch indentation in the SP disk microspecimen.This method, in its essence, is similar to the method of instrumented indentation test. The difference is that the latter method refers to the nondestructive test methods, whereas the SP-test method requires special disk-shaped specimens whose geometry and surface roughness have to meet rather severe requirements. It is advisable to use this method if traditional tensile tests according to the standard GOST 1497-84 [10] are impossible because of the necessity of preparing specimens from miniature cut-outs. In the world practice, the method of punching SP disk microspecimens is used to determine the characteristics of strength s u , s 0 2 . [2-9] and fracture toughness J c I , K c