... .The Certificate of First-Class Management of exporting Goods Type: Spring WasherMaterial: Carbon Steel, Alloy Steel, Stainless SteelFinish: Plain, Black, Zinc ... : 1mm-100mmOutside Diameter: 3mm-500mmThickness: 0.1mm-6mmGrade: 4.8, 6.8, 8.8, 10.9 Our products have passed the evaluation of ISO9001 ... Management of exporting Goods which awarded by CCIB of China. Spring Washer