... , 40cr, 38crsi, Magnesium alloy, etc.Surface treatmentNickel plating, zinc coating, chrome plating, and oxidation, Polishing, chrome plating, phosphating etcCNC machining Tolerance+/-0.02mm( iron parts ... non-standard precision machining parts4.Surface treatment: polishing,zinc plating,gold plating,nickel plating or chrome plating,anodizing and painting. Ferrous turning products by CNC ...