采用ISO14017:2014，其中规定了螺纹从M1,6到M64（含）的六角头螺钉的特性，螺纹M1,6到M24（含）的产品等级为A级，标称长度为10 d或150 mm（以较短者为准），以及螺纹超过M24（含）或标称长度超过10 d或150 mm（以较短者为准）的产品等级为B级。

Adopts ISO4017:2014, which specifies the characteristics of hexagon head screws with threads from M1,6 up to and including M64, of product gradeA for threads M1,6 to M24 and nominal lengths up to and including 10 d or 150mm, whichever is the shorter, and product grade B for threads over M24 or nominal lengths over 10 d or 150mm, whichever is the shorter.