美制螺纹标准(粗细牙螺纹)

1、美制内螺纹（2B）常用规格极限尺寸表（细牙）UNF公称尺寸和 每英寸牙数小径极限取小 取人中径极限取小 取人大径min底孔直径取小 取人8-32 UNC (0.164-32)0.13000.13903.30203.53060.14370.14753.65003.74650.16404.16563.403.5010-24 (0.190-24)0.14500.15603.68303.96240.16290.16724.13774.24690.19004.82603.753.9012-24 (0.216-24)0.17100.18104.34344.59740.18890.19334.79814.9

2、0980.21605.48644.404.551/4-20 (0.250-20)0.19600.20704.97845.25780.21750.22245.52455.64900.25006.35005.055.205/16-18 (0.3175-18)0.2520 0.26506.40086.73100.27640.28177.02067.15520.31257.93756.456.603/8-16 (0.375-16)0.30700.32107.79788.15340.33440.34018.49388.63850.37509.52507.858.007/16-14 (0.4375-14)

3、0.36000.37609.14409.55040.39110.39729.933910.08890.437511.11259.209.401/2-13 (0.50-13)0.41700.434010.5918 11.02360.45000.456511.4300 11.59510.500012.700010.65 10.909/16-12 (0.5625-12)0.47200.490011.9888 12.44600.50840.515212.9134 13.08610.562514.287512.05 12.305/8-11 (0.625-11)0.52700.546013.3858 3.

4、86840.56600.573214.376414.55930.625015.875013.45 13.703/4-10 (0.750-10)0.64200.663016.306816.84020.68500.692717.399017.59460.750019.050016.40 16.707/8-9 (0.875-9)0.75500.778019.1770 19.76120.80280.811020.391120.59940.875022.225019.30 19.601-8 (1.000-8)0.86500.890021.971022.60600.91880.927623.3375 23

5、.56101.000025.400022.10 22.401 .底孔直径指攻丝前钻孔直径，铸铁、黄铜等较软料取小值，钢、2 .标记示例：10-24UNC-2B(或 0.190-24UNC-2B)、3/8-16UNC-2B(或 0.375-16UNC-2B)青铜等较硬料取大值。公称尺寸和小径极限中径极限大径min底孔直径每英寸牙数最小最大最小最大最小最大8-36 UNF 0.1340 0.1420 0.1460 0.1496 0.1640 3.45 3.67(0.164-36)3.4036 3.6068 3.7084 3.7998 4.165610-320.1560 0.1640 0.1697

6、0.1736 0.1900 4.00 4.27(0.190-32)3.9624 4.1656 4.3104 4.4094 4.826012-280.1770 0.1860 0.1928 0.1970 0.2160 4.55 4.85(0.216-28)4.4958 4.7244 4.8971 5.0038 5.48641/4-280.2110 0.2200 0.2268 0.2311 0.2500 5.40 5.71(0.250-28)5.3594 5.5880 5.7607 5.8699 6.35005/16-240.2670 0.2770 0.2854 0.2902 0.3125 6.85

7、 7.20(0.3175-24)6.7818 7.0358 7.2492 7.3711 7.93753/8-240.3300 0.3400 0.3479 0.3528 0.3750 8.45 8.78(0.375-24)8.3820 8.6360 8.8367 8.9611 9.52507/16-200.3830 0.3950 0.4050 0.4104 0.4375 9.85 10.23(0.4375-20)9.7282 10.0330 10.2870 10.4242 11.11251/2-200.4460 0.4570 0.4675 0.4731 0.5000 11.40 11.82(0.

8、50-20)11.3284 11.6078 11.8745 12.0167 12.70009/16-180.5020 0.5150 0.5264 0.5323 0.5625 12.85 13.31(0.5625-18)12.7508 13.0810 13.3706 13.5204 14.28755/8-180.5650 0.5780 0.5889 0.5949 0.6250 14.45 14.89(0.625-18)14.3510 14.6812 14.9581 15.1105 15.87503/4-160.6820 0.6960 0.7094 0.7159 0.7500 17.40 17.9

9、5(0.750-16)17.3228 17.6784 18.0188 18.1839 19.05007/8-140.7980 0.8140 0.8286 0.8356 0.8750 20.35 20.97(0.875-14)20.2692 20.6756 21.0464 21.2242 22.22501-120.9100 0.9280 0.9459 0.9535 1.0000 23.90 23.95(1.000-12)23.1140 23.5712 24.0259 24.2189 25.40001.底孔直径指攻丝前钻孔直径，铸铁、黄铜等较软料取小值，钢、青铜等较硬料取大值。2.标记示例：10-

10、32UNF-2B(或 0.190-32UNF-2B) 、3/8-24UNF-2B(或 0.375-24UNF-2B)美制外螺纹(2A常用规格极限尺寸表(粗牙)UNC螺胚直径最小 最大公称尺寸 / 大径极限 中径极限小径 max每英寸牙数最小 最大最小 最大8-32 UNC 0.1571 0.1631 0.1399 0.1428 0.1248 3.58 3.61(0.164-32)3.99034.14273.55353.62713.169910-240.18180.18900.15860.16190.13794.074.10(0.190-24)4.61774.80064.02844.11233.

11、502712-240.20780.21500.18450.18790.16394.724.75(0.216-24)5.27815.46104.68634.77274.16311/4-200.24080.24890.21270.21640.18765.455.48(0.250-20)6.11636.32215.40265.49664.76505/16-180.3026 0.3113 0.2712 0.2752 0.2431 6.94 6.98(0.3175-18) 7.6860 7.9070 6.8885 6.9901 6.17473/8-160.3643 0.3737 0.3287 0.333

12、1 0.2970 8.40 8.44(0.375-16)9.2532 9.4920 8.3490 8.4607 7.54387/16-140.4258 0.4361 0.3850 0.3897 0.3485 9.83 9.87(0.4375-14) 10.8153 11.0769 9.7790 9.8984 8.85191/2-130.4876 0.4985 0.4435 0.4485 0.4041 11.34 11.38(0.50-13)12.3850 12.6619 11.2649 11.3919 10.26419/16-120.5495 0.5609 0.5016 0.5068 0.45

13、87 12.80 12.84(0.5625-12) 13.9573 14.2469 12.7406 12.8727 11.65105/8-110.61130.62340.55890.56440.511914.2714.32(0.625-11)15.5270 15.8344 14.1961 14.3358 13.00233/4-100.73530.74820.67730.68320.625517.2817.33(0.750-10)18.6766 19.0043 17.2034 17.3533 15.88777/8-90.85920.87310.79460.80090.736820.27 20.3

14、2(0.875-9)21.823722.176720.182820.342918.71471-80.98300.99800.91000.91680.844623.22 23.27(1.000-8)24.968225.349223.114023.286721.45281. 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)美制外螺纹(2A常用规格极限尺寸表(细牙)UNF公称尺寸和每英寸牙数螺纹系列代号大

15、径极限 中径极限小径 max 螺胚直径最小 最大 最小 最大最小 最大8-36 UNF 0.1577 0.1632 0.1424 0.1452 0.1291 3.65 3.67(0.164-36)4.00564.14533.61703.68813.279110-320.18310.18910.16580.16880.15084.244.27(0.190-32)4.65074.80314.21134.28753.830312-280.20850.21500.18860.19180.17124.824.85(0.216-28)5.29595.46104.79044.87174.34851/4-28

16、0.24250.24900.22250.22580.20525.695.71(0.250-28)6.15956.32465.65155.73535.21215/16-240.3042 0.3114 0.2806 0.2843 0.2603 7.17 7.20(0.3175-24) 7.7267 7.9096 7.1272 7.2212 6.61163/8-240.3667 0.3739 0.3430 0.3468 0.3228 8.75 8.78(0.375-24)9.3142 9.4971 8.7122 8.8087 8.19917/16-200.4281 0.4362 0.3995 0.4

17、037 0.3749 10.19 10.23(0.4375-20) 10.8737 11.0795 10.1473 10.2540 9.52251/2-200.4906 0.4987 0.4619 0.4662 0.4374 11.78 11.82(0.50-20)12.4612 12.6670 11.7323 11.8415 11.11009/16-180.5524 0.5611 0.5205 0.5250 0.4929 13.27 13.31(0.5625-18) 14.0310 14.2519 13.2207 13.3350 12.51975/8-180.61490.62360.5828

18、0.58750.555414.8514.89(0.625-18)15.618515.839414.803114.922514.10723/4-160.73910.74850.70290.70790.671817.9117.95(0.750-16)18.773119.011917.853717.980717.06377/8-140.86310.87340.82160.82700.785820.9320.97(0.875-14)21.922722.184420.868621.005819.95931-120.98680.99820.93820.94410.896023.9023.95(1.000-

19、12)25.064725.354323.830323.980122.75841. 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)螺纹代号 Thread Code一、 英制螺纹 (螺纹牙型角 55 度) Thread of British standard ( Thread pitch shape angle 55)BSWA英国标准惠氏螺纹(粗牙)British Standard Whitworth Thread ( Coarse

20、)BSF英国标准惠氏螺纹(细牙)British Standard Whitworth Thread ( Fine )G直管螺纹(外螺纹分 A、B两面级、丝锥分G G D) Straight pipe thread ( Outside )thread in AB: taps in G、 G D )R锥管外螺纹 (旧代号 ZG;KG Outside paper pipe thread ( Old thread code ZG,KG )RC锥管内螺纹(旧代号 ZG;KG Inside taper pipe thread ( Old thread code ZG,KG )二、美制螺纹(螺纹牙型角 60 度) Thread of American standard ( Thread pitch shape angle 60 UNC统一制粗牙螺纹(代替 NQ Unified coarse pitch thread ( Instead of NC )UNF统一制细牙螺纹(代替 NF) Unified fi