In this paper, a novel plane strain small punch test (SPT) method is proposed for material plastic properties characterization. The plane strain SPT is different from the standard SPT in the two ways: (a) a long thin rectangular specimen (with dimensions of about 20mm×8mm×0.5mm) is used, and (b) the resulting test tool components - such as punch head and upper and lower die - are also different. The punch head is a prism with a half-circular shape and the upper and lower die consists of left and right long blocks, with a chamfer at each of the inner top corners of the lower die. The tool components have been designed and assembled and the plane strain small punch tests have been performed to obtain the punch force and the corresponding central displacements of the specimen. This information is then used to characterize the material's plastic parameters
