(1000pcs) DIN 6923 M4 Hexagon Flange Nuts with Serration A4 Stainless Steel, Ships Free in USA by Aspen Fasteners, ASSP692344: Amazon.com: Industrial & Scientific
300pcs) DIN 6923 M8 Hexagon Flange Nuts Without Serration A4 Stainless Steel, Ships Free in USA by Aspen Fasteners, ASSP6923408: Amazon.com: Industrial & Scientific