... :1.Material:steel(1022,1006,10B21),stainless steel,2..Surface:zinc(white,blue,yellow,black),plain3.Size:It's ... material of hardness can be go to HRC55 . ♦ Bright surface . Parts are plated in chromed nickel .♦ Exquisite package . for more easy ... plastic colored boxes , which marked all information for parts .♦ Long - service . Parts have good comprehensive mechanical properties after quenching .♦ Easy ...