Abstract: A self-drilling stud particularly suited for use in normal weight or lightweight composite deck system where the use of standard weld studs is inappropriate because of the relatively thin material cross-section of the steel support member. The stud is heat treated to a dual-hardness level so that a portion of the stud is capable of drilling the support member and the decking. The remaining portion of the stud remains relatively ductile so that it can withstand and transfer shear loads imposed by shifting of the concrete slab which overlies the decking to the main support members. The stud is a single piece fastener which includes specially formed annular flanges which enhance interlocking between the stud, the concrete slab and support members.