M3 M4 M5 M6 M8 M10 M12 A2 STAINLESS STEEL WING NUTS BUTTERFLY NUT DIN 315. SIZES: M3 M4 M5 M6 M8 M10. A2 STAINLESS STEEL BUTTERFLY WING NUTS DIN 315. A2 stainless steel is commonly referred to as 18-8 since it contains 18% chromium and 8% nickel.
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