For the production of severely cold-headed ware, such as a phillips screw, the material requires good cold headability, In this paper the optimum austenite grain size range for good cold headability of stable austenitec stainless steel is discussed. After simulating the cold heading process of phillips screw with the aid of ABAQUS 5.2, the effect of austenite grain size on cold headability is investigated by compression test with drop-weight-tear tester. This result has a good agreement with that of tensile test. The optimm austenite grain size for cold heading is considered to be form 45㎛ tp 60㎛ because of the formation of deformation twins and the prevention of orange peel effect at the surface.