ABNT NBR ISO 2857 Versão Corrigida 1-2011 ISO公制螺纹公差4H到8H和4G至6G的粗，细球场的地面螺纹丝锥 - 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
This Standard specifies the manufacturing tolerances on the threaded portion of taps for producing the ISO metric threads of tolerances classes 4H to 8H and 4G to 6G as defined in ABNT NBR ISO 965-1 to 3 (excluding, consequently, classes 7G and 8G considered as usually produced with ground thread taps).