Iji 40Cr ígwè, na siri ike dabere na usoro ch?r?, mb? siri ike machining, quenching na tempering okpom?k? ?gw?gw? HRC30-35, ?kara emecha na finishing mb?ne, na n'ikpeaz?-egweri iji h? na elu ngwaah?a b? nchara-proofed, siri d? na nch?p?ta ndidi.