1美制外螺纹（2A）常用规格极限尺寸表（粗牙）大径极限中径极限螺胚直径公称尺寸和每英寸牙数螺纹系列代号最小最大最小最大小径max最小最大8-320.15710.16310.13990.14280.1248(0.164-32)3.99034.14273.55353.62713.16993.583.6110-240.18180.18900.15860.16190.1379(0.190-24)4.61774.80064.02844.11233.50274.074.1012-240.20780.21500.18450.18790.1639(0.216-24)5.27815.46104.68634.77274.16314.724.751/4-200.24080.24890.21270.21640.1876(0.250-20)6.11636.32215.40265.49664.76505.455.485/16-180.30260.31130.27120.27520.2431(0.3175-18)7.68607.90706.88856.99016.17476.946.983/8-160.36430.37370.32870.33310.2970(0.375-16)9.25329.49208.34908.46077.54388.408.447/16-140.42580.43610.38500.38970.3485(0.4375-14)10.815311.07699.77909.89848.85199.839.871/2-130.48760.49850.44350.44850.4041(0.50-13)12.385012.661911.264911.391910.264111.3411.389/16-120.54950.56090.50160.50680.4587(0.5625-12)13.957314.246912.740612.872711.651012.8012.845/8-110.61130.62340.55890.56440.5119(0.625-11)15.527015.834414.196114.335813.002314.2714.323/4-100.73530.74820.67730.68320.6255(0.750-10)18.676619.004317.203417.353315.887717.2817.337/8-90.85920.87310.79460.80090.7368(0.875-9)21.823722.176720.182820.342918.714720.2720.321"-80.98300.99800.91000.91680.8446(1.000-8)UNC24.968225.349223.114023.286721.452823.2223.271.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)（注：表中上行斜体数值单位为英寸，下行为毫米）2美制外螺纹（2A）常用规格极限尺寸表（细牙）大径极限中径极限螺胚直径公称尺寸和每英寸牙数螺纹系列代号最小最大最小最大小径max最小最大8-360.15770.16320.14240.14520.1291(0.164-36)4.00564.14533.61703.68813.27913.653.6710-320.18310.18910.16580.16880.1508(0.190-32)4.65074.80314.21134.28753.83034.244.2712-280.20850.21500.18860.19180.1712(0.216-28)5.29595.46104.79044.87174.34854.824.851/4-280.24250.24900.22250.22580.2052(0.250-28)6.15956.32465.65155.73535.21215.695.715/16-240.30420.31140.28060.28430.2603(0.3175-24)7.72677.90967.12727.22126.61167.177.203/8-240.36670.37390.34300.34680.3228(0.375-24)9.31429.49718.71228.80878.19918.758.787/16-200.42810.43620.39950.40370.3749(0.4375-20)10.873711.079510.147310.25409.522510.1910.231/2-200.49060.49870.46190.46620.4374(0.50-20)12.461212.667011.732311.841511.110011.7811.829/16-180.55240.56110.52050.52500.4929(0.5625-18)14.031014.251913.220713.335012.519713.2713.315/8-180.61490.62360.58280.58750.5554(0.625-18)15.618515.839414.803114.922514.107214.8514.893/4-160.73910.74850.70290.70790.6718(0.750-16)18.773119.011917.853717.980717.063717.9117.957/8-140.86310.87340.82160.82700.7858(0.875-14)21.922722.184420.868621.005819.959320.9320.971"-120.98680.99820.93820.94410.8960(1.000-12)UNF25.064725.354323.830323.980122.758423.9023.951.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)3美制内螺纹（2B）常用规格极限尺寸表（粗牙）小径极限中径极限底孔直径公称尺寸和每英寸牙数螺纹系列代号最小最大最小最大大径min最小最大8-320.13000.13900.14370.14750.1640(0.164-32)3.30203.53063.65003.74654.16563.403.5010-240.14500.15600.16290.16720.1900(0.190-24)3.68303.96244.13774.24694.82603.753.9012-240.17100.18100.18890.19330.2160(0.216-24)4.34344.59744.79814.90985.48644.404.551/4-200.19600.20700.21750.22240.2500(0.250-20)4.97845.25785.52455.64906.35005.055.205/...
