440C Stainless Steel Sphere, Grade G100, Mirror-Like Finish, A276/A756/Ams 5630, 1" Diameter, 0.0001" Sphericity (Pack Of 3) 440C stainless steel is wear resistant and can be heat treated to very high hardness ratings, surpassing the hardness of 440a and 440B stainless steel Mirror-like finish provides a bright, reflective appearance Meets A276, A756, and AMS 5630 specifications