ISO 4161:2012规定了带法兰的六角螺母(2型)的特性,其公制粗螺纹为M5至M20(含M5至M20),对于M16以下的螺纹,其产品等级为A级,对于M16以上的螺纹,其产品等级为B级。
ISO 4161:2012 specifies the characteristics of hexagon nuts with flange (style 2), with metric coarse threads from M5 to M20 inclusive, of product grade A for threads up to and including M16 and product grade B for threads above M16.