... 4.height:10MM/12.5MM/14MM/20MM(mm) Product Typebarrel nuts MaterialStainless steel, Carbon Steel, Aluminum alloy, Zinc alloy, copper, ... Turning, Milling, Drilling, threading, stampling, punching etc..Surface finishPolishing, and Chrome plating, zinc plating, blackening, Nickel plating, ElectrophoresisColorMetal colors ... term cooperation with you! sell excellent quality barrel nuts in hardware