supply large quantity flat washer with different standards, such as ANSI/ASME, DIN, BS, JIS ISO,GB,UNI and NON STANDAR 1. Standard: ANSI/ASME, DIN, BS, IFI, JIS ISO,GB and NON STANDARD2. Surface finish:plain, black oxide, Zinc plated (blue,white and yellow) chrome plated, Cr+3,Cr+6,H.D.G, Nickle-plate, Dacromet..sheradizing3. Material:70#,SS304,SS316,Q235B,45#,50#,65Mn,Brass,phosphoruscopper ...