M6 M8 M10 M12 M14 M16 M18 M20. Material Carbon Stee（Colored Zinc） / 304 A2 Stainless Steel / 316 A4 Stainless Steel. Stainless steel belongs to the austenitic stainless steel, austenite in the cold working process in part or a small amount of transformation to martensite, martensite is magnetic, so stainless steel is non-magnetic or slightly magnetic.
