For miniature sheet type tensile tests on 316 SS, it is well known that for thin specimens or large grains relative to the specimen thickness, the mechanical properties vary with specimen thickness and the ratio of the specimen thickness to the grainsize. However, the effects of specimen thickness and grainsize on mechanical properties obtained from the shear punch test have not yet been investigated systematically. The current study examines the effect of specimen thickness and grainsize on mechanical properties obtained from the shear punch test. Sheet stock of five different thicknesses ranging from 0.1 mm to 0.3 mm were constructed from 316 stainless steel. Two different heat treatments were used to provide two different grainsizes. Effective shear yield strength and effective shear ultimate strength were measured from shear punch tests at each thickness and grainsize. A measure of strain hardening was also obtained from the data. The results were compared to open literature data from a similar study using miniature tensile specimens. The results show that the shear punch test does not have the same sensitivity as the miniature tensile test for the range of specimen thicknesses and grainsizes examined.