M12-M33 ,10 Class, Hardness: HRC26-36, fully hardened and tempered to match ... or samples.Machanism Capability: Bolts: 10.9 Class, minimum tensile strength 170,000 psi.Nuts:M12-M33 ,10 Class, Hardness: HRC26-36, fully ... fasteners/ hex Nuts /zinc wheel nut DIN934 JIS 8.8/10