管螺纹尺寸.doc

尺寸代号每英寸牙数螺 距螺纹 直 径（in)np大径D、d小径D1、d11/16280.9077.7236.5611/8280.9079.7288.5661/4191.33713.15711.4453/8191.33716.66214.951/2141.81420.95518.6315/8141.81422.91120.5873/4141.81426.44124.1177/8141.81430.20127.8771112.30933.24930.2911-1/8112.30937.89734.9391-1/4112.30941.9138.9521-1/2112.30947.80344.8451-3/4112.30953.74650.7882112.30959.61456.6562-1/4112.30965.7162.7522-1/2112.30975.18472.2262-3/4112.30981.53478.5783112.30987.88484.9263-1/2112.309100.3397.3724112.309113.03110.0725112.309138.43135.4726112.309163.83160.872注：1in=25.4mm1、用螺纹密封的管螺纹其标记及各种螺纹的特征代号规定如下：Rc圆锥内螺纹Rp与圆锥外螺纹配合的圆柱内螺纹R圆锥外螺纹标准规定将螺纹尺寸代号写在特征代号之后，若螺纹为械旋应再加写左旋代号LH，具体示例如下：圆锥内螺纹：Rc1/2左旋圆柱内螺纹：Rp1/2LH圆柱内螺纹与圆锥外螺纹的配合：Rp2/R22、非螺纹密封的管螺纹标记如下：A级外螺纹：G1/2A内螺纹：G1/2左旋B级外螺纹：G1/2BLH螺纹副G1/2G1/2A1、公制螺纹所标注的公称尺寸即直径值，而英制要所标注的尺寸乘以25.4，才等与其直径值。2、公制螺纹的牙型角为60度，而英制螺纹的牙型角为55度。3、公制螺纹螺距就是其相邻两牙在中径线上对应两点间的轴向距离。而英制螺纹的螺距可由1英寸长度内的牙数换算出来。公称通径DN/mm俗称相当管螺纹/in外径D/mm61分管1/81082分管1/4103分管3/814或17154分管1/218或22206分管3/425或27251寸管132或34尺寸代号每25.4mm内的牙数n螺距p牙高h圆弧半径r基面上的直径基准长度基本有效螺纹长度装配余量大径（基准直径）d=D中径d2小径d1=D1余量圈数1/16280.9070.5810.1257.7237.1426.56146.52.52+3/41/8280.9070.5810.1259.7289.1478.56646.52.52+3/41/4191.3370.8560.18413.15712.30111.44569.73.72+3/43/8191.3370.8560.18416.66215.80614.956.410.13.72+3/41/2141.8141.1620.24920.95519.79318.6318.213.252+3/43/4141.8141.1620.24926.44125.27924.1179.514.552+3/41112.3091.4790.31733.24931.7730.29110.416.86.42+3/41+1/4112.3091.4790.31741.9140.43138.95212.719.16.42+3/41+1/2112.3091.4790.31747.80346.32444.84512.719.16.42+3/42112.3091.4790.31759.61458.13556.65615.923.47.53+1/42+1/2112.3091.4790.31775.18473.70572.22617.526.79.243112.3091.4790.31787.88486.40584.92620.629.89.243+1/2112.3091.4790.317100.3398.85197.37222.231.49.244112.3091.4790.317113.03111.551110.07225.435.810.44+1/45112.3091.4790.317138.43136.951135.47228.640.111.556112.3091.4790.317163.83162.351160.87228.640.111.551.本标准包括了圆锥内螺纹和圆柱内螺纹与圆锥外螺纹两种联接形式。2.本标准适用于管子、管接头、旋塞、阀门和其它螺纹联接的附件。3.当内螺纹的结构无螺尾时，有效螺纹的长度不应小于表中最小值的80%。4.与圆锥外螺纹配合的圆柱内螺纹，其各直径的极限偏差均为圆锥内螺纹基面轴向位移的确良/16。5. 标记示例：螺纹特征代号：R表示圆锥外螺纹；Rc表示圆锥内螺纹；Rp表示圆柱内螺纹公称直径为1 1/2的圆锥内螺纹：Rc1 1/2公称直径为1 1/2的圆柱内螺纹与圆锥外螺纹组成的螺纹副：Rp1 1/2 / R1 1/2公称直径为1 1/2的圆锥内螺纹与圆锥外螺纹组成的螺纹副：Rc1 1/2 / R1 1/2当螺纹为左旋时 Rc 1 1/2 / R1 1/2 -LH6. 示图中：内、外圆锥螺纹