英制普通螺纹 (惠氏螺纹) -- 小螺纹系列 (BA) 名义尺寸牙型代号大径螺距每英寸牙 数中径小径牙型高 BAmmmmtpimm外螺纹H1d=Dpd2=D2d3No. 14BA10.23110.40.860.720.14No. 13BA1.20.25101.61.050.90.15No. 12BA1.30.2890.711.130.960.17No. 11BA1.50.3181.931.3151.130.185No. 10BA1.70.3572.571.491.280.21No. 9BA1.90.3965.121.6651.430.235No. 8BA2.20.4359.071.941.680.26No. 7BA2.50.4852.922.211.920.29No. 6BA2.80.5347.922.482.160.32No. 5BA3.20.5943.052.8452.490.355No. 4BA3.60.6638.483.2052.810.395No. 3BA4.10.7334.793.663.220.44No. 2BA4.70.8131.354.2153.730.485No. 1BA5.30.928.224.764.220.54