最小最大最小最大最小最大8‐320.15710.16310.13990.14280.1248(0.164‐32)3.99034.14273.55353.62713.169910‐240.18180.1890.15860.16190.1379(0.190‐24)4.61774.80064.02844.11233.502712‐240.20780.2150.18450.18790.1639(0.216‐24)5.27815.4614.68634.77274.16311/4‐200.24080.24890.21270.21640.1876(0.250‐20)6.11636.32215.40265.49664.7655/16‐180.30260.31130.27120.27520.2431(0.3175‐18)7.6867.9076.88856.99016.17473/8‐160.36430.37370.32870.33310.297(0.375‐16)9.25329.4928.3498.46077.54387/16‐140.42580.43610.3850.38970.3485(0.4375‐14)10.815311.07699.7799.89848.85191/2‐130.48760.49850.44350.44850.4041(0.50‐13)12.38512.661911.264911.391910.26419/16/20120.54950.56090.50160.50680.4587(0.5625‐12)13.957314.246912.740612.872711.6515/8‐110.61130.62340.55890.56440.5119(0.625‐11)15.52715.834414.196114.335813.00233/4‐100.73530.74820.67730.68320.6255(0.750‐10)18.676619.004317.203417.353315.88777/8‐90.85920.87310.79460.80090.7368(0.875‐9)21.823722.176720.182820.342918.71471"‐80.9830.9980.910.91680.8446(1.000‐8)24.968225.349223.11423.286721.4528美制外螺纹（2A）常用规格极限尺寸表（粗牙）公称尺寸和每英寸牙数螺纹系列代号大径极限中径极限小径max螺胚直径4.14.724.755.455.486.946.988.48.449.839.8711.3411.3812.812.8414.2714.3217.2817.3320.2720.3223.2223.271.螺胚直径指滚丝前的尺寸，数值为依经验公式计算而得，在实践中需验证。2.标记示例：10‐24UNC‐2A(或0.190‐24UNC‐2A)、3/8‐16UNC‐2A(或0.375‐16UNC‐2A)UNC3.583.614.07（注：表中上行斜体数值单位为英寸，下行为毫米）美制螺纹标准对照表最小最大最小最大最小最大8‐360.15770.16320.14240.14520.1291(0.164‐36)4.00564.14533.6173.68813.279110‐320.18310.18910.16580.16880.1508(0.190‐32)4.65074.80314.21134.28753.830312‐280.20850.2150.18860.19180.1712(0.216‐28)5.29595.4614.79044.87174.34851/4‐280.24250.2490.22250.22580.2052(0.250‐28)6.15956.32465.65155.73535.21215/16‐240.30420.31140.28060.28430.2603(0.3175‐24)7.72677.90967.12727.22126.61163/8‐240.36670.37390.3430.34680.3228(0.375‐24)9.31429.49718.71228.80878.19917/16‐200.42810.43620.39950.40370.3749(0.4375‐20)10.873711.079510.147310.2549.52251/2‐200.49060.49870.46190.46620.4374(0.50‐20)12.461212.66711.732311.841511.119/16/20180.55240.56110.52050.5250.4929(0.5625‐18)14.03114.251913.220713.33512.51975/8‐180.61490.62360.58280.58750.5554(0.625‐18)15.618515.839414.803114.922514.10723/4‐160.73910.74850.70290.70790.6718(0.750‐16)18.773119.011917.853717.980717.06377/8‐140.86310.87340.82160.8270.7858(0.875‐14)21.922722.184420.868621.005819.95931"‐120.98680.99820.93820.94410.896(1.000‐12)25.064725.354323.830323.980122.7584美制外螺纹（2A）常用规格极限尺寸表（细牙）公称尺寸和每英寸牙数螺纹系列代号大径极限中径极限小径max螺胚直径4.274.824.855.695.717.177.28.758.7810.1910.2311.7811.8213.2713.3114.8514.8917.9117.9520.9320.9723.923.951.螺胚直径指滚丝前的尺寸，数值为依经验公式计算而得，在实践中需验证。2.标记示例：10‐32UNF‐2A(或0.190‐32UNF‐2A)、3/8‐24UNF‐2A(或0.375‐24UNF‐2A)UNF3.653.674.24最小最大最小最大最小最大8‐320.130.1390.14370.14750.164(0.164‐32)3.3023.53063.653.74654.165610‐240.1450.1560.16290.16720.19(0.190‐24)3.6833.96244.13774.24694.82612‐240.1710.1810.18890.19330.216(0.216‐24)4.34344.59744.79814.90985.48641/4‐200.1960.2070.21750.22240.25(0.250‐20)4.97845.25785.52455.6496.355/16‐180.2520.2650.27640.28170.3125(0.3175‐18)6.40086.7317.02067.15527.93753/8‐160.3070.3210.33440.34010...
