... ,S60C;US Standard:AISI1020,AISI1040,AISI1045,AISI1050;Europe Standard:CK15,C.22,C45,CK45,C60,CK60;C45E;Alloy Steel:Chinese Standad ... Test:According GB/T6401-91 Class 1,Class 2,Class 3; And GB/T6402-2008 Class 3,Class 2; And Sep1921 Class C/c,D/d,E/e ...