公英制螺纹对照表#优质严制

1、英语和公制对照表英制统一螺纹在英制国家广泛使用。这种螺纹可分为三个系列：粗齿螺纹，细齿螺纹，UNFF螺纹，固定螺距螺纹。标记方法：螺纹直径.每英寸齿数系列代码.精度等级示例：粗齿系列3/8-16unc-2a细齿系列3/8-24unf-2a超细齿系列3/832 UNFF2A定距系列3/820联合国2A第一个数字3/8表示螺纹的外径，单位为英寸，当换算成公制单位毫米时，它乘以25.4，即3/825.4=9.525毫米；第二和第三位数16、24、32和20是每英寸的齿数(长度为25.4毫米的齿数)；第三位数字后的文字代码UNC、UNF、UNFF和UN是系列代码，最后两位数字2A是精度等级。在统一的螺

2、纹标准中，公称尺寸可以有不同的螺距。例如，1/2可分为13齿、16齿、20齿和32齿。该标准规定，13颗牙为粗牙，20颗牙为细牙，28颗牙为超细牙；16齿和32齿被称为恒定齿距，这与粗齿和细齿没有区别。英制螺纹外径公制对照表英寸公制英寸公制英寸公制4#2.91-5/841.2754-5/8117.4755#3.21-3/444.454-3/4120.656#3.51-7/847.6254-7/8123.8257#3.9250.851278#4.22-1/853.9755-1/4133.3510#4.82-1/457.155-3/8136.52512#5.52-3/860.3255-1/2139

3、.714#/1/46.352-1/263.55-5/8142.8751/83.1752-5/866.6755-3/4146.051/46.352-3/469.855-7/8149.2255/167.9362-7/873.0256152.43/89.525376.26-1/4158.757/1611.1133-1/879.3756-3/8161.9251/212.73-1/482.556-1/2168.2759/1614.2883-3/885.7256-5/8171.455/815.8753-1/288.96-3/4174.6253/419.053-5/892.0256-7/8177.87/82

4、2.2253-3/495.257184.15125.43-7/898.1257-1/4187.3251-1/828.5754101.67-3/8190.51-1/431.754-1/4107.957-1/2193.6751-3/834.9254-3/8111.1257-5/8196.851-1/238.14-1/2114.37-3/4200.025英美联盟公制规格井底规格井底1-64UNC1.55M1.0*0.250.752-56UNC1.8M1.1*0.250.853-48UNC2.1M1.2*0.250.954-40UNC2.3M1.4*0.31.15-40UNC2.6M1.6*0.351

5、.256-32UNC2.8M1.7*0.351.358-32UNC3.4M1.8*0.351.4510-32UNC4.1M2.0*0.41.610-24UNC3.9M2.2*0.451.7512-24UNC4.5M2.3*0.41.914-20UNC5.1M2.5*0.452.1516-18unc6.6M2.6*0.452.238-16UNC8M3.0*0.52.5716-14UNC9.4M3.0*0.62.412-13UNC10.8M3.5*0.62.9916-12UNC12.2M4.0*0.73.358-11UNC13.6M4.0*0.753.2534-10UNC16.5M4.5*0.73

6、.878-9UNC19.5M5*0.84.21 - 8UNC22.2M5*0.94.1118-7UNC25M6*1.05114-7UNC28.2M7*1.06138-6UNC30.8M8*1.256.8112-6UNC34M9*1.257.8134-5UNC39.5M10*1.58.52-412UNC45.2M11*1.59.5英美接头螺纹的螺距是根据每英寸长度的齿数计算的外径按螺纹牌号第一代码计算(特殊外径4#、5#、6#、7#、8#、10#和12#详见表1)示例：1/4-20 UNC1/4*25.4=6.35(螺纹外径)25.4/20=1.27(间距)M12*1.7510.3M14*2.0

7、12M16*2.014M18*2.515M20*2.517M22*2.519M24*3.021M27*3.024M30*3.526.5螺纹电极外径和螺距参考表英美联盟公制规格外径规格外径1-64UNC1.45M1.0*0.250.652-56UNC1.7M1.1*0.250.753-48UNC2.0M1.2*0.250.854-40UNC2.2M1.4*0.31.05-40UNC2.5M1.6*0.351.156-32UNC2.7M1.7*0.351.258-32UNC3.3M1.8*0.351.3510-32UNC4.0M2.0*0.41.510-24UNC3.8M2.2*0.451.651

8、2-24UNC4.4M2.3*0.41.814-20UNC5.0M2.5*0.452.0516-18unc6.5M2.6*0.452.138-16UNC7.9M3.0*0.52.4716-14UNC9.3M3.0*0.62.312-13UNC10.7M3.5*0.62.8916-12UNC12.1M4.0*0.73.358-11UNC13.5M4.0*0.753.1534-10UNC16.4M4.5*0.73.778-9UNC19.4M5*0.84.11 - 8UNC22.1M5*0.94.0118-7UNC24.9M6*1.04.9114-7UNC28.1M7*1.05.9138-6UNC30.7M8*1.256.7112-6UNC33.9M9*1.257.7134-5UNC39.4M10*1.58.42-412UNC45.1M11*1.59.4英美接头螺纹的螺距是根据每英寸长度的齿数计算的示例：1/4-20 UNC1/4*25.4=6.35(螺纹外径)25.4/2