美制外螺纹常用规格尺寸表

1、文档编码 : CJ6I9D7W8A6 HD4M9Q9N10I3 ZZ1M10F7E10Z4美制外螺纹（ 2A）常用规格极限尺寸表（粗牙）公称尺寸和 螺纹系 大径极限 中径极限 螺胚直径小径 max 每英寸牙数 列代号 最小 最大 最小 最大 最小 最大8-32 0.1571 0.1631 0.1399 0.1428 0.1248 3.58 3.61 0.164-32 3.9903 4.1427 3.5535 3.6271 3.1699 10-24 0.1818 0.1890 0.1586 0.1619 0.1379 4.07 4.10 0.190-24 4.6177 4.8006 4.0284

2、 4.1123 3.5027 12-24 0.2078 0.2150 0.1845 0.1879 0.1639 4.72 4.75 0.216-24 5.2781 5.4610 4.6863 4.7727 4.1631 1/4-20 0.2408 0.2489 0.2127 0.2164 0.1876 5.45 5.48 0.250-20 6.1163 6.3221 5.4026 5.4966 4.7650 5/16-18 0.3026 0.3113 0.2712 0.2752 0.2431 6.94 6.98 0.3175-18 7.6860 7.9070 6.8885 6.9901 6.1

3、747 3/8-16 0.3643 0.3737 0.3287 0.3331 0.2970 8.40 8.44 0.375-16 9.2532 9.4920 8.3490 8.4607 7.5438 7/16-14 0.4258 0.4361 0.3850 0.3897 0.3485 UNC 9.83 9.87 0.4375-14 10.8153 11.0769 9.7790 9.8984 8.8519 1/2-13 0.4876 | 0.4985 0.4435 0.4485 0.4041 11.34 11.38 0.50-13 12.3850 12.6619 11.2649 11.391 1

4、0.2641 9/16-12 0.5495 | 0.5609 0.5016 9 0.5068 0.4587 12.80 12.84 0.5625-12 13.9573 14.2469 12.7406 12.872 11.6510 5/8-11 0.6113 1 0.6234 0.5589 7 0.5644 0.5119 14.27 14.32 0.625-11 15.5270 15.8344 14.1961 14.335 13.0023 3/4-10 0.7353 1 0.7482 0.6773 8 0.6832 0.6255 17.28 17.33 0.750-10 18.6766 19.0

5、043 17.2034 17.353 15.8877 7/8-9 0.8592 1 0.8731 0.7946 3 0.8009 0.7368 20.27 20.32 0.875-9 21.8237 22.1767 20.1828 20.342 18.7147 1-8 1 0.9830 0.9980 0.9100 9 0.9168 0.8446 23.22 23.27 1.000-8 24.9682 25.3492 23.1140 23.286 21.4528 1. 螺胚直径指滚丝前的尺寸,数值为依体会公式运算而得,在实践中需验证；| 7 2. 标记示例： 10-24UNC-2A （或 0.1

6、90-24UNC-2A）、3/8-16UNC-2A （或 0.375-16UNC-2A）（注：表中上行斜体数值单位为英寸,下行乘 25.4 为毫米）精选范本美制外螺纹（ 2A）常用规格极限尺寸表（细牙）公称尺寸和螺纹系最小大径极限最大最小中径极限最大小径 max 螺胚直径每英寸牙数最小最大列代号8-36 UNF 0.1577 0.1632 0.1424 0.1452 0.1291 3.65 3.67 0.164-36 4.0056 4.1453 3.6170 3.6881 3.2791 10-32 0.1831 0.1891 0.1658 0.1688 0.1508 4.24 4.27 0.1

7、90-32 4.6507 4.8031 4.2113 4.2875 3.8303 12-28 0.2085 0.2150 0.1886 0.1918 0.1712 4.82 4.85 0.216-28 5.2959 5.4610 4.7904 4.8717 4.3485 1/4-28 0.2425 0.2490 0.2225 0.2258 0.2052 5.69 5.71 0.250-28 6.1595 6.3246 5.6515 5.7353 5.2121 5/16-24 0.3042 0.3114 0.2806 0.2843 0.2603 7.17 7.20 0.3175-24 7.726

8、7 7.9096 7.1272 7.2212 6.6116 3/8-24 0.3667 0.3739 0.3430 0.3468 0.3228 8.75 8.78 0.375-24 9.3142 9.4971 8.7122 8.8087 8.1991 7/16-20 0.4362 0.4037 10.19 10.23 0.4281 0.3995 0.3749 0.4375-20 10.8737 11.0795 10.1473 10.2549.5225 0.4906 |0 0.4662 1/2-20 0.4987 0.4619 0.4374 11.78 11.82 0.50-20 12.4612

9、 12.6670 11.7323 11.841 5 0.5250 11.1100 9/16-18 0.5524 0.5611 0.5205 13.27 13.31 0.4929 14.0310 14.2519 13.2207 13.33512.5197 0.5625-18 0.6149 10 0.5875 5/8-18 0.6236 0.5828 0.5554 14.85 14.89 14.1072 0.625-18 15.6185 0.7391 115.8394 14.8031 14.922 5 0.7079 3/4-16 0.7485 0.7029 0.6718 17.91 17.95 0

10、.750-16 18.7731 19.0119 17.8537 17.98017.0637 0.8631 17 0.8270 7/8-14 0.8734 0.8216 0.7858 20.93 20.97 0.875-14 21.9227 1 0.9868 22.1844 20.8686 21.005 8 0.9441 19.9593 1-12 0.9982 0.9382 0.8960 23.90 23.95 1.000-12 25.0647 25.3543 23.8303 23.98022.7584 |1 1.螺胚直径指滚丝前的尺寸,数值为依体会公式运算而得,在实践中需验证2.标记示例：10

11、-32UNF-2A 或 0.190-32UNF-2A、3/8-24UNF-2A或 0.375-24UNF-2A 精选范本美制内螺纹（ 2B）常用规格极限尺寸表（粗牙）公称尺寸和螺纹系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列代号0.1640 8-32 0.1300 0.1390 0.1437 0.1473.40 3.50 3.6500 5 3.7460.164-32 3.3020 3.5306 4.1656 5 10-24 UN0.1450 0.1560 0.1629 0.1670.1900 3.75 3.90 2 0.190-24 3.6830 3.9624

12、4.1377 4.246J 4.8260 0.2160 9 12-24 4.40 4.55 0.1710 0.1810 0.1889 0.1933 0.216-24 4.7981 4.9094.3434 4.5974 5.4864 8 1/4-20 5.05 5.20 0.1960 0.2070 0.2175 0.2220.2500 4 0.250-20 4.9784 | 5.2578 5.5245 5.649| 6.3500 0.3125 0 6.45 6.60 5/16-18 0.2520 0.2650 0.2764 0.2817.0206 0.3344 8.4938 0.3911 9.9

13、339 0.4500 7 2 1 5 7.155 0.3408.638 0.3976.4008 | 6.7310 | 7.9375 0.3750 0.3175-18 3/8-16 7.85 8.00 0.3070 0.3210 0.375-16 7.7978 | 8.1534 | 9.5250 0.4375 7/16-14 0.3600 0.3760 9.20 9.40 C 2 10.0889 0.4560.4375-14 9.1440 | 9.5504 | 11.1125 0.5000 1/2-13 0.4170 0.4340 10.65 10.90 11.4300 0.5084 12.91

14、34 0.5660 14.3764 0.6850 17.3990 0.8028 20.3911 0.9188 23.3375 5 11.595 1 0.515 2 13.086 1 0.573 2 14.559 3 0.692 7 17.594 6 0.811 0 20.599 0.927 6 23.561 0 0.50-13 10.5918 11.0236 12.7000 9/16-12 0.4720 0.4900 0.5625 12.05 12.30 11.9888 0.5270 12.4460 1 0.5460 1 14.2875 0.6250 0.5625-12 5/8-11 13.4

15、5 13.70 0.625-11 13.3858 0.6420 13.8684 1 0.6630 1 15.8750 0.7500 3/4-10 16.40 16.70 16.3068 0.7550 16.8402 1 0.7780 1 19.0500 0.8750 0.750-10 7/8-9 19.30 19.60 0.875-9 19.1770 19.7612 22.2250 1-8 0.8650 0.8900 1.0000 22.10 22.40 1.000-8 21.9710 | 22.6060 | 25.4000 1.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

16、硬料取大值；2.标记示例：10-24UNC-2B 或 0.190-24UNC-2B、3/8-16UNC-2B或 0.375-16UNC-2B 精选范本美制内螺纹（ 2B）常用规格极限尺寸表（细牙）公称尺寸和螺纹系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列代号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 4.1656 10-32 4.00 4.27 0.1560 0.1640 0.1697 0.1736 0.1900 0.190-

17、32 3.9624 4.1656 4.3104 4.4094 4.8260 4.55 4.85 12-28 0.1770 0.1860 0.1928 0.1970 0.2160 0.216-28 4.4958 4.7244 4.8971 5.0038 5.4864 1/4-28 5.40 5.71 0.2268 0.2311 0.2500 0.2110 0.2200 0.250-28 6.3500 5.3594 5.5880 5.7607 5.8699 5/16-24 6.85 7.20 0.2670 0.2770 0.2854 0.2902 0.3125 0.3175-24 6.7818 7

18、.0358 7.2492 7.3711 7.9375 3/8-24 8.45 8.78 0.3300 0.3400 0.3479 0.3528 0.3750 0.375-24 8.3820 8.6360 8.8367 8.9611 9.5250 9.85 10.23 7/16-20 0.4050 0.4104 0.3830 0.3950 0.4375 0.4375-20 9.7282 10.0330 10.2870 0.4675 10.424 2 0.4731 11.1125 1/2-20 0.4460 0.4570 0.5000 11.40 11.82 0.50-20 11.3284 11.6078 11.8745 0.5264 12.016 7 0.5323 12.7000 9/16-18 0.5020