... 40CR ETC, carbon steel ,stainless steel5.Finish surface:Zinc plated , Yellow Zinc plated , balck , plain 6.Packing: bulk , box packing , 25kgs/ctn , ... or other special materials. For finishing, we provide black oxide, zinc electroplating, phosphate, copper plating, mechanical galvanization, hot dip galvanization, ... or upon our customers' special requirements, in grades 4.8, 6.8, 8.8, 10.9, 12.9, A2-50, ...