M4 flange nuts with locking teeth (pack of 100), made of steel, galvanised, for bolts/screws, closure, certified standard DIN 6923, serated flange nuts (4 mm) : Amazon.de: DIY & Tools
Amazon.co.jp: 5 M14-1.5 六角フランジナット - 非鋸歯クラス10亜鉛 DIN 6923 / ISO 4161 : DIY・工具・ガーデン
Amazon.com: 10 M14-2.0 Hexagon Flange Nut - with Serrations Class 8 Zinc. DIN 6923 : Industrial & Scientific
1000pcs) DIN 6923 M3 Hexagon Flange Nuts with Serration A4 Stainless Steel, Ships Free in USA by Aspen Fasteners, ASSP692343: Amazon.com: Industrial & Scientific
M8 Serrated Flanged Hexagon Nuts (DIN 6923) - Zinc Plated High Tensile Steel (8.8)
Amazon.co.jp: 5 M12-1.5 六角フランジナット - 非鋸歯クラス8亜鉛 DIN 6923 / ISO 4161 : DIY, Tools & Garden