英制螺纹标准对照表.doc

英制,公制螺纹对照表. 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 55度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/R2左旋B级外螺纹：G1/2BLH螺纹副G1/2G1/2A内螺纹：G1/2英制螺纹标准JISB0203,JISB2301(mm)#01.52#11.85#22.18#32.51#42.84#53.18#63.51#73.84#84.17#104.83#125.481/46.35UNS是英制普通粗牙螺纹;UNF是英制航空标示皆将分母为8,再直接称分子之番号.Ex:1/8x0.50PPB:1分牙螺丝x0.50”长,PPBEx:5/16x0.50PPB=2.5/8x0.50-PPB:2分半牙螺丝x0.50”长,PPBEx:5/32x0.50PPB=1.25/8x0.50-PPB:1分2厘半螺丝x0.50”长,PPBEx:1/4x0.50-PPB=2/8x0.50-PPB:2分牙螺丝x0.50”长,PPB注:有时会标示粗牙或细牙.UNF:细牙:电子业较常用.UNC:粗牙:重机械结构较常用.Ex:3/8x0.50,UNFPPB:3分细牙螺丝x0.50”长,PPB.C-2:LengthCode:为英寸标示,须乘以25.40换算为mm.用扣规量，与公制牙型吻合是公制螺纹，与英制螺纹吻合是英制螺纹。也可以用卡尺量螺纹的外径，和螺距。公制螺纹外径是以毫米为单位，如6，8，10，12，18，20毫米等等螺距也是以毫米为单位，如0.5,0.75,1,1.5,2,3,等等英制螺纹外径是以英寸为单位，（每英寸等于25.4毫米）如3/16,5/8,1/4,1/2,等等所以用公制卡尺量外径读数常带不规则的小数。英制螺距是用每英寸含多少个牙表示。把卡尺定在25.4毫米，把一个尺尖对齐螺纹牙尖，另一个尺尖如对齐螺纹牙尖就是英制螺纹，如对不齐螺纹牙尖应该是公制螺纹。测量螺距时最好把螺纹的牙尖倒印在白粉笔上，粉笔上的印比较清晰，便于测量。测公制螺距应该测量一段长度，如10，15，20，毫米等等，数一下含多少牙，算出螺距用英寸为单位规定螺纹规格的为英制螺纹，如：G1。用公制单位毫米规定螺纹规格的为公制螺纹。如：M30。英制是一英寸(24.5厘米)内有多少牙来定的,一般是55度角.公制是两牙尖的间距是多少MM来定的螺距,英制粗牙螺纹标准 螺紋尺寸下孔徑嵌合率A列(硬材質)B列(軟材質)A列直徑B列直徑內螺紋最小徑內螺紋最大徑W1/82.62.570.783.070.088.33/163.73.678.485.870.088.31/45.15.076.983.070.588.35/166.66.574.099.570.188.43/88.07.975.080.069.588.27/169.49.373.780.069.088.81/210.710.573.881.269.088.29/1612.312.073.484.469.088.25/813.713.573.580.369.688.53/416.716.572.378.469.688.37/819.519.375.480.970.188.4122.422.073.883.671.088.211/825.024.876.981.372.088.411/428.328.074.380.772.088.413/830.530.381.685.373.888.611/233.833.579.384.873.888.615/836.035.781.185.774.888.313/439.239.080.783.874.888.317/841.841.580.684.774.788.4245.044.780.284.474.788.4英制管用螺纹标准管用螺紋尺寸JISB0203JISB2301錐管內螺紋Rc(PT)平行內螺紋Rp(PS)錐管內螺紋計算值下孔徑計算值下孔徑計算值下孔徑1/166.2306.26.4906.51/88.2358.28.4958.58.1918.21/410.94110.911.34111.410.94510.93/814.42814.414.84614.914.38814.41/217.9501818.48918.517.943183/423.3492323.9752423.30523129.4232930.1113029.3532911/437.9403838.7723937.8903811/243.8334444.5654543.72043255.4125556.4765655.4065521/270.7017172.0097270.78870383.2018384.7098583.3648331/295.5479697.1559795.747954107.834108109.855110108.3221085133.110133135.255135133.5971336158.510159160.655161158.8101587183.360183185.9541868208.560209211.3542129233.960234236.75423710259.166259262747310312.875313英制管螺纹对照表-英制锥管螺纹对照表公称直径螺距 低孔直径低孔深度G1/4 1.337 11.4 20(19)G3