1.own factory. OEM 2.can be heat treatment by ourself. 3.can be finished various of surface according to customer's required Product Description Detail:Hex bolt Bolt Standard: DIN 933, DIN 931, DIN 558, JIS ISO, BS, ANSI...etc Material: 35#,45#, SUS304,SUS316 etcSurface Finish: Various of finish is available, such as Zinc plate, plain finish, copper plate, nickel plate H.D.G chromium plate ...