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500pcs) DIN 6923 M5 Hexagon Flange Nuts Without Serration A4 Stainless Steel, Ships Free in USA by Aspen Fasteners, ASSP6923405: Amazon.com: Industrial & Scientific
Amazon.com: 25 M10-1.5 Hexagon Flange Nut with Serrations Class 10 Zinc DIN 6923/ISO 4161 : Industrial & Scientific