... SS201,202,302,304,316...copper is shiny brass , pure copper,such as H62,H65,H68 ... head...Socket typePhillip type,Pozi type,Eleven type,hexagonal type,Torx type,trangle type,slotted point type,square type,Combined type...FinishZinc plated,Nickel ... Experience ,good technology1.We are a professional manufacturer with more than 20 years experiences in screw ... Stainless Steel hollow threaded rod accessory