Shanghai Jinrui Norm Parts Supplies Co., Ltd. was built in 2001 which located in Baoshan District adjacent to the Bao Steel Group.Shanghai Jinrui is a fastener enterprise who owes a set of R & D,Website:http://www.chinajinrui.net, design, production and sales of high quality.GB Standard flat washer covers the dimensional requirments of metric series FLAT WASHER.The standard of GB Standard flat washer GB97 and GB96,the former is nomal flat washer and the second is large washer.The flat washer is widely used, mainly goes with bolt and screw. The mechanical property has 100HV, 140HV, 200HV and 300HV.  StandardGradeFinshGB97 GB96100HV     white zinc      yellow zinc black oxide      H.D.G       Dacromet      ...140HV200HV300HV