Material:iron,malleable,pearlitccasting,grade 70003 or 60004,astm-a220;optional material:iron,modular graphitic(ductile iron),grade 80-55-06;heat treatment:harden indicated surfaces iaw spec mil-s-12515,hardened depth 0.015 in.Min.Hardness ra 74.5 min;final protective finish:1.4.3.1 of mil-std-171,0.0010 in.Thick