... experience in special fastener Name: hex nut with internal thread and castle screw Ability for the material of this kind of ... ,9.8,10.9,12.9,etcCarbon steelGr.B,Gr.C,Gr.D,Gr.36,Gr.58,1010,1015,1016,1020,1045,etcAlloy steel4130,4140 ... plating Light oil,spray coating,electrophoretic coating,etc Polishing Grinding and polishing,etc,except mirror finishAbility for the tolerance: Roundess0.002mmCylindricity0 ...