EN 22857-1989 ISO制螺纹公差为4H到8H以及4G到6G的粗螺距和细螺距用磨制丝锥.螺纹部分的制造公差
Ground thread taps for ISO metric threads of tolerances 4H to 8H and 4G to 6G coarse and fine pitches; manufacturing tolerances on the threaded portion (ISO 2857:1973 encl. AMD 1:1984 and AMD 2:1986)