supply large quantity flat washer with different standards, such as ANSI/ASME, DIN, BS, JIS ... , BS, IFI, JIS ISO,GB and NON STANDARD2. Surface finish:plain, black oxide, Zinc plated (blue,white and yellow) chrome plated ... #,50#,65Mn,Brass,phosphoruscopper beryllium copper,Aluminium,alloy steel flat washer/plain washer