Sizes:M3 M4 M5 M6 M8 M10, M12, M16. High quality Stainless Steel hexagon washers also known as a serrated washers type S made of durable A2 stainless steel. What is A2 Stainless Steel?. A2 stainless steel is commonly referred to as 18-8 since it contains 18% chromium and 8% nickel.
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