1、螺纹底孔直径参考美标螺纹钻头直径螺纹代号 粗牙ASP60C CarbideNo.1-64UNC 1.55 No.2-56UNC 1.80 No.3-48UNC 2.10 No.4-40UNC 2.30 No.5-40UNC 2.60 No.6-32UNC 2.80 No.8-32UNC 3.40 No.10-24UNC 3.90 No.12-24UNC 4.50 1/4-20UNC 5.10 5/16-18UNC 6.60 3/8-16UNC 8.00 7/16-14UNC 9.40 1/2-13UNC 10.80 9/16-12UNC 1220 5/8-11UNC 13.60 3/4-10U
2、NC 1650 7/8-9UNC 19.50 1-8UNC 22.20 11/8-7UNC 25.00 钻头直径螺纹代号 细牙ASP60C CarbideNo.0-80UNF 1.25 No.1-72UNF 1.55 No.2-64UNF 185 No.3-56UNF 2.10 No.4-48UNF 2.40 No.5-44UNF 2.70 No.6-40UNF 2.90 No.8-36UNF 3.50 No.10-32UNF 4.10 No.12-28UNF 4.60 1/4-28UNF 5.50 5/16-24UNF 6.90 3/8-24UNF 8.50 7/16-20UNF 9.90 1/2-20UNF 11.50 9/16-18UNF 12.90 5/8-18UNF 14.50 3/4-16UNF 17 7/8-14UNF 20.50 1-12UNF 23.20
