螺纹攻牙底孔大小

攻牙底孔的使用参数表
一、螺紋下孔徑表
1、公制粗牙螺紋 JIS B 0209-1982(單位：mm)
註(1)M1.4以下等級：5H、M1.6以上等級：6H (2)基於JIS B 0209-1982標準2、公制細牙螺紋-01 JIS B 0211-1982(單位：mm)
單位：mm)
(2)基於JIS B 0211-1982標準
3、美制粗牙螺紋 (單位：mm)
4、美制細牙螺紋 (單位：mm)
5、英制粗牙螺紋 (單位：mm)
6、英制管用螺紋 (單位：mm)
7、美制管用耐密斜行螺紋(NPTF‧NPSF) (單位：mm)
8、公制螺紋(NRT) (單位：mm)
二、螺紋下孔徑表(無屑絲攻用)
1、美制細牙螺紋(NRT) (單位：mm)
2、英制管用平行螺紋(NRT) (單位：mm)
3、公制螺紋(HRT) (單位：mm)
4、公制粗牙螺紋 HL-NRT (單位：mm)
三、螺紋下孔徑表(護套螺紋用)
1、公制粗牙螺紋 (單位：mm)
2、公制細牙螺紋 (單位：mm)
3、美制粗牙螺紋 (單位：mm)
mm)
各種換算表
美制螺絲外徑公厘(mm)換算表
山數節距換算表。

开牙钻孔尺寸计算公式五金工作中经常会遇到攻牙（套丝）开孔的尺寸，总结了一下攻牙开孔的尺寸表和公式，有需要的时候可以查表直接用或自己计算。

切削螺纹加工计算公式（范围参考公式）：底孔大小=螺纹外径-0.9倍螺距例如：加工不锈钢M8螺纹，1.25螺距，底孔大小=8-0.9*1.25=6.8 挤压螺纹加工计算公式（范围参考公式）：底孔大小=螺纹外径-螺距/2例如：加工不锈钢M8螺纹，1.25螺距，底孔大小=8-1.25/2=7.3 挤牙时孔不能偏小，偏小容易断丝锥，所以一般不能大于这个值。

公式：牙外径－1/2×牙距例1：公式：M3×0.5＝3－(1/2×0.5)＝2.75mm M6×1.0＝6－(1/2×1.0)＝5.5mm例2：公式：M3×0.5＝3－(0.5÷2)＝2.75mm M6×1.0＝6－(1.0÷2)＝5.5mm普通螺纹钻底孔用钻头直径尺寸计算公式:P<1 mm时Do = d-P P>1 mm时Do = d-(1~1.1)PP---螺距(mm)Do---攻螺纹前钻头直径(mm)d---螺纹公称直径(mm)普通螺纹直径与螺距M1x0.25M24× 3M1.2×0.25M30× 3.5M1.6×0.35 M36× 4M2×0.4M42× 4.5 M2.5×0.45M48× 5M3×0.5M56×5.5M4× 0.7 M64×6M5×0.8挤牙螺纹底孔计算公式; M6× 1M8× 1.25 d=螺纹公称直径-P/2 M10 ×1.5M12×1.75M16× 2M20×2.5。

螺纹攻牙底孔参数攻牙底孔的使用参数表一、螺紋下孔徑表1、公制粗牙螺紋JIS B 0209-1982(單位：mm)螺纹尺寸钻头直径螺纹下孔徑內螺紋小徑最小直径最大直径M1×0.25 0.75 0.78 (80%) 0.729 0.785 1.1 ×0.25 0.85 0.88 (80%) 0.829 0.885 1.2 ×0.25 0.95 0.98 (80%) 0.929 0.985 1.4 ×0.3 1.1 1.14 (80%) 1.075 1.142 1.6 ×0.35 1.25 1.32 (75%) 1.221 1.321 1.8 ×0.35 1.45 1.52 (75%) 1.421 1.521 2×0.4 1.6 1.65 (80%) 1.567 1.679 2.2 ×0.45 1.75 1.83 (75%) 1.713 1.838 2.5 ×0.45 2.1 2.13 (75%) 2.013 2.138 3×0.5 2.5 2.59 (75%) 2.459 2.599 3.5 ×0.6 2.9 3.01 (75%) 2.850 3.010 4×0.7 3.3 3.39 (80%) 3.242 3.422 4.5 ×0.75 3.8 3.85 (80%) 3.688 3.878 5×0.8 4.2 4.31 (80%) 4.134 4.334 6×15 5.13 (80%) 4.917 5.153 7×16 6.13 (80%) 5.917 6.153 8×1.25 6.86.85 (85%) 6.647 6.912 9×1.257.87.85 (85%) 7.647 7.912 10×1.58.5 8.62 (85%) 8.376 8.676 11×1.59.5 9.62 (85%) 9.376 9.676 12×1.75 10.3 10.40 (85%) 10.106 10.441 14×2 12 12.2 (85%) 11.835 12.210 16×2 14 14.2 (85%) 13.835 14.210 18×2.5 15.5 15.7 (85%) 15.294 15.744 20×2.5 17.5 17.7 (85%)17.294 17.744 22×2.5 19.5 19.2 (85%) 19.294 19.744 24×3 21 21.2 (85%) 20.752 21.252 27×3 24 24.2 (85%) 23.752 24.252 30×3.5 26.5 26.6 (90%) 26.211 26.771 33×3.5 29.5 29.6 (90%) 29.211 29.771 36×4 32 32.1 (90%) 31.670 32.270 39 ×4 35 35.1 (90%) 34.670 35.270 42 ×4.5 37.5 37.6 (90%) 37.129 37.799 45 ×4.5 40.5 40.6 (90%) 40.129 40.799 48 ×5 43 43.1 (90%) 42.587 43.297 註(1)M1.4以下等級：5H、M1.6以上等級：6H (2)基於JIS B 0209-1982標準2、公制細牙螺紋-01JIS B 0211-1982(單位：mm)螺纹尺寸钻头直径螺纹下孔徑內螺紋小徑最小直径最大直径M2.5 ×0.35 2.2 2.22 (75%) 2.121 2.221 3×0.35 2.7 2.72 (75%) 2.621 2.7213.5 ×0.35 3.2 3.22 (75%) 3.121 3.2214×0.5 3.5 3.59 (75%) 3.459 3.5994.5 ×0.5 4 4.09 (75%) 3.959 4.0995×0.5 4.5 4.59 (75%) 4.459 4.5995.5 ×0.5 5 5.09 (75%) 4.959 5.0996×0.75 5.3 5.35 (80%) 5.188 5.3787×0.75 6.3 6.35 (80%) 6.188 6.3788×1 7 7.13 (80%) 6.917 7.1538×0.75 7.3 7.35 (80%) 7.188 7.3789×1 8 8.13 (80%) 7.917 8.1539×0.75 8.3 8.35 (80%) 8.188 8.37810×1.25 8.8 8.85 (85%) 8.647 8.91210×1 9 9.13 (80%) 8.917 9.15310×0.75 9.3 9.35 (80%) 9.188 9.37811 ×1 10 10.13 (80%) 9.917 10.15311 ×0.75 10.3 10.35 (80%) 10.188 10.37812 ×1.5 10.5 10.62 (85%) 10.376 10.676 12 ×1.25 10.8 10.85 (85%) 10.647 10.912 12 ×1 11 11.13 (80%) 10.917 11.15314 ×1.5 12.5 12.62 (85%) 12.376 12.67614 ×1 13 13.13 (80%) 12.917 13.15315 ×1.5 13.5 13.62 (85%) 13.376 13.67615 ×1 14 14.13 (80%) 13.917 14.15316 ×1.5 14.5 14.62 (85%) 14.376 14.67616 ×1 15 15.13 (80%) 14.917 15.15317 ×1.5 15.5 15.62 (85%) 15.376 15.676 17 ×1 16 16.13 (80%) 15.917 16.15318 ×2 16 16.2 (85%) 15.835 16.21018 ×1.5 16.5 16.62 (85%) 16.376 16.67618 ×1 17 17.13 (80%) 16.917 17.15320 ×2 18 18.2 (85%) 17.835 18.21020 ×1.5 18.5 18.62 (85%) 18.376 18.67620 ×1 19 19.13 (80%) 18.917 19.15322 ×2 20 20.2 (85%) 19.835 20.21022 ×1.5 20.5 20.62 (85%) 20.376 20.67622 ×1 21 21.13 (80%) 20.917 21.15324 ×2 22 22.2 (85%) 21.835 22.21024 ×1.5 22.5 22.62 (85%) 22.376 22.67624 ×1 23 23.13 (80%) 22.917 23.15325 ×2 23 23.2 (85%) 22.835 23.21025 ×1.5 23.5 23.62 (85%) 23.376 23.67625 ×1 24 24.13 (80%) 23.917 24.153公制細牙螺紋-02JIS B 0211-1982(單位：mm)螺纹尺寸钻头直径螺纹下孔徑內螺紋小徑最小直径最大直径M26 ×1.5 24.5 24.62 (85%) 24.376 24.676 27 ×2 25 25.2(85%) 24.835 25.210 27 ×1.5 25.5 25.62 (85%) 25.376 25.67627 ×1 26 26.13 (80%) 25.917 26.15328 ×2 26 26.2(85%) 25.835 26.210 28 ×1.5 26.5 26.62 (85%) 26.376 26.676 28 ×1 27 27.13 (80%) 26.917 27.153 30 ×3 27 27.2 (85%) 26.752 27.252 30 ×2 28 28.2 (85%) 27.835 28.210 30 ×1.528.5 28.62 (85%) 28.376 28.676 30 ×1 29 29.13 (80%) 28.91729.153 32 ×2 30 30.2 (85%) 29.835 30.21032 ×1.5 30.5 30.62 (85%) 30.376 30.67633 ×3 30 30.2 (85%) 29.752 30.252 33 ×2 31 31.2 (85%) 30.835 31.210 33 ×1.5 31.5 31.62 (85%) 31.376 31.67635 ×1.5 33.5 33.62 (85%) 33.376 33.67636 ×3 33 33.2 (85%) 32.752 33.252 36 ×2 34 34.2 (85%) 33.835 34.210 36 ×1.5 34.5 34.62 (85%) 34.376 34.67638 ×1.5 36.5 36.62 (85%) 36.376 36.67639 ×3 36 36.2 (85%) 35.752 36.252 39 ×2 37 37.2 (85%) 36.835 37.21039 ×1.5 37.5 37.62 (85%) 37.376 37.67640 ×3 37 37.2 (85%) 36.752 37.252 40 ×2 38 38.2 (85%)37.835 38.210 40 ×1.5 38.5 38.62 (85%) 38.376 38.676 42 ×4 3838.1 (90%) 37.670 38.270 42 ×3 39 39.2 (85%) 38.752 39.252 42 ×2 40 40.2 (85%) 39.835 40.210 42 ×1.5 40.5 40.62 (85%) 40.37640.676 45 ×4 41 41.1 (90%) 40.670 41.270 45 ×3 42 42.2 (85%)41.752 42.252 45 ×2 43 43.2 (85%) 42.835 43.210 45×1.5 43.5 43.62 (85%) 43.376 43.676 48 ×4 44 44.1 (90%) 43.670 44.270 48 ×3 45 45.2 (85%) 44.752 45.252 48 ×2 46 46.2 (85%) 45.835 46.21048 ×1.5 46.5 46.62 (85%) 46.376 46.676 50 ×3 47 47.2 (85%) 46.752 47.252 50 ×2 48 48.2 (85%) 47.835 48.210 50 ×1.5 48.5 48.62 (85%) 48.376 48.676 註(1)等級：6H(2)基於JIS B 0211-1982標準3、美制粗牙螺紋(單位：mm)螺纹尺寸钻头直径2B级螺纹下孔徑內螺紋小徑最小直径最大直径NO.1 -64UNC 1.55 1.57 (65%) 1.425 1.5822 -56 1.8 1.86 (65%) 1.695 1.8713 -48 2.1 2.14 (65%) 1.941 2.1464 -40 2.3 2.36 (70%) 2.157 2.3855 -40 2.6 2.69 (70%) 2.487 2.6976 -32 2.8 2.86 (75%) 2.642 2.89510 -24 3.9 3.91 (80%) 3.683 3.96212 -24 4.5 4.57 (80%) 4.344 4.5971/4 -20 5.1 5.25 (80%) 4.979 5.257 5/16-18 6.6 6.72 (80%) 6.401 6.731 3/8 -16 8 8.15 (80%) 7.798 8.153 7/16 -14 9.4 9.50 (80%) 9.144 9.550 1/2 -13 10.8 11.0 (80%) 10.592 11.023 9/16 -12 12.2 12.3 (85%) 11.989 12.446 5/8-11 13.6 13.8 (85%) 13.38613.868 3/4-10 16.5 16.8 (80%) 16.307 16.840 7/8-9 19.5 19.6 (85%) 19.177 19.761 1 -8 22.2 22.5 (85%) 21.971 22.60611/8 -7 25 25.2 (85%) 24.638 25.349 11/4 -7 28.2 28.4 (85%) 27.813 28.524 13/8 -6 30.8 31.0 (85%) 30.353 31.115 11/2 -6 34 34.2 (85%) 33.528 34.290 13/4 -5 39.5 39.8 (85%) 38.964 39.8272 - 4 45.2 45.3 (90%) 44.679 45.593 4、美制細牙螺紋(單位：mm)螺纹尺寸钻头直径2B级螺纹下孔徑內螺紋小徑最小直径最大直径NO.0-80UNF 1.25 1.30 (65%) 1.182 1.3051 -72 1.55 1.61 (65%) 1.474 1.6122 -64 1.85 1.90 (65%) 1.756 1.9123 -56 2.1 2.17 (70%) 2.025 2.1974 -48 2.4 2.44 (70%) 2.271 2.4585 -44 2.7 2.74 (70%) 2.551 2.7406 -40 2.9 3.02 (70%) 2.820 3.0228 -36 3.5 3.59 (75%) 3.404 3.60610 -32 4.1 4.14 (80%) 3.963 4.16512 -28 4.6 4.70 (80%) 4.496 4.7241/4 -28 5.5 5.56 (80%) 5.360 5.5885/16-24 6.9 7.02 (80%) 6.782 7.0357/16-20 9.9 10.01 (80%) 9.729 10.0331/2 -20 11.5 11.60 (80%) 11.329 11.6079/16 -18 12.9 13.07 (80%) 12.751 13.0815/8 -18 14.5 14.65 (80%) 14.351 14.6813/4 -16 17.5 17.59 (85%) 17.323 17.6787/8 -14 20.5 20.6(85%) 20.270 20.6751-12 23.2 23.5(85%) 23.114 23.5711 1/8 -12 26.5 26.7(80%) 26.289 26.7461 1/4 -12 29.5 29.9(80%) 29.464 29.9211 3/8 -12 32.8 33.0(85%) 32.639 33.0961 1/2 -12 36 36.2(85%) 35.814 36.2715、英制粗牙螺紋(單位：mm)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W 1/8 2.6 2.5 70.7 83.0 70.0 88.3 3/16 3.7 3.6 78.4 85.8 70.0 88.3 1/4 5.1 5.0 76.9 83.0 70.5 88.3 5/16 6.6 6.5 74.0 99.5 70.1 88.4 3/8 8.0 7.9 75.0 80.0 69.5 88.2 7/16 9.4 9.3 73.7 80.0 69.0 88.8 1/2 10.7 10.5 73.8 81.2 69.0 88.2 9/16 12.3 12.0 73.4 84.4 69.0 88.2 5/8 13.7 13.5 73.5 80.3 69.6 88.5 3/4 16.7 16.5 72.3 78.469.6 88.3 7/8 19.5 19.3 75.4 80.9 70.1 88.4 1 22.4 22.0 73.8 83.6 71.0 88.2 1 1/8 25.0 24.8 76.9 81.3 72.0 88.4 1 1/4 28.3 28.0 74.3 80.7 72.0 88.4 1 3/8 30.5 30.3 81.6 85.3 73.8 88.6 1 1/2 33.8 33.5 79.3 84.8 73.8 88.6 1 5/8 36.0 35.7 81.1 85.7 74.8 88.3 1 3/4 39.2 39.0 80.7 83.8 74.8 88.31 7/8 41.8 41.5 80.6 84.7 74.7 88.42 45.0 44.7 80.2 84.4 74.7 88.46、英制管用螺紋(單位：mm)管用螺紋尺寸JIS B 0203JIS B 2301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1/16 6.230 6.2 6.490 6.5 －－1/8 8.235 8.2 8.495 8.5 8.191 8.2 1/4 10.941 10.9 11.341 11.4 10.945 10.9 3/8 14.428 14.4 14.846 14.9 14.388 14.4 1/2 17.950 18 18.489 18.5 17.943 18 3/4 23.349 23 23.975 24 23.305 23 1 29.423 29 30.111 30 29.353 29 1 1/4 37.940 38 38.772 39 37.890 381 1/2 43.833 44 44.565 45 43.720 432 55.412 55 56.476 56 55.406 552 1/2 70.701 71 72.009 72 70.788 703 83.201 83 84.709 85 83.364 833 1/2 95.547 96 97.155 97 95.747 954 107.834 108 109.855 110 108.322 1085 133.110 133 135.255 135 133.597 1336 158.510 159 160.655 161 158.810 1587 183.360 183 185.954 1868 208.560 209 211.354 2129 233.960 234 236.754 23710 259.166 259 262.154 26212 309.747 310 312.875 3137、美制管用耐密斜行螺紋(NPTF?NPSF) (單位：mm)管用螺紋尺寸斜行螺紋(NPTF)平行螺紋(NPSF)鑽頭直徑鑽頭直徑使用鉸刀場合不使用鉸刀場合1/16 －0.234 ( 5.94) 0.246 ( 6.25) 1/4 0.250 ( 6.35)1/8 21/64 0.328 ( 8.33) 0.339 ( 8.61) 11/32 0.344 ( 8.74)1/4 27/64 0.422 (10.72) 7/16 0.438 (11.13) －0.444 (11.28)3/8 9/16 0.562 (14.27) 37/64 0.578 (14.68) 37/64 0.578 (14.68) 1/2 11/16 0.688 (17.48) 45/64 0.703 (17.86) 23/32 0.719 (18.26)3/4 57/64 0.891 (22.63) 59/64 0.922 (23.42) －0.922 (23.42)1 1 1/8 1.125 (28.58) 15/321.156 (29.36) 1 5/32 1.156 (29.36)1 1/4 1 15/32 1.469 (37.31) 11/21.500 (38.10) －－1 1/2 1 45/64 1.703 (43.26) 147/641.734 (44.04) －－2 2 3/16 2.188 (55.58) 27/322.219 (56.36) －－2 1/2 2 19/32 2.594 (65.89) 241/642.641 (67.08) －－上述鑽頭直徑來源於美制管用耐密斜行螺紋ANSI B1.20.3—1957 Dryseal Pipe Threads (Inch)標準8、公制螺紋(NRT) (單位：mm)螺紋尺寸1級螺紋用下孔徑2級螺紋用下孔徑RH 精度最小～最大(嵌合率％)RH精度最小～最大(嵌合率％)M 1×0.25 2 0.87 ~ 0.89(100~85) 4 0.90 ~0.92 (100~80)1.1×0.25 2 0.97 ~ 0.99(100~85) 4 1.00 ~1.02 (100~80) 1.2×0.252 1.07 ~ 1.09(100~85) 4 1.10 ~1.12 (100~80) 1.4×0.3 2 1.244~ 1.263(100~85)4 1.270~1.294 (100~80)1.7×0.35 2 1.51 ~ 1.54(100~80) 4 1.54 ~ 1.58 (100~75)2 ×0.4 2 1.78 ~ 1.82(100~80) 4 1.81 ~ 1.85 (100~75) 2.3×0.4 2 2.08 ~ 2.12(100~80) 4 2.11 ~ 2.15 (100~75) 2.5×0.45 2 2.25 ~2.29(100~80) 4 2.28 ~ 2.33 (100~75)2.6×0.45 2 2.35 ~ 2.39(100~80) 4 2.38 ~ 2.43 (100~75)3 ×0.5 3 2.74 ~ 2.78(100~80)5 2.76 ~ 2.81 (100~75)3.5×0.6 3 3.18 ~ 3.21(100~85) 5 3.20 ~ 3.26 (100~75)4 ×0.7 4 3.63 ~ 3.67(100~85) 6 3.65 ~ 3.70 (100~85)5 ×0.8 4 4.57 ~ 4.62(100~85)6 4.59 ~ 4.66 (100~80)6 ×1 4 5.45 ~ 5.51(100~85)7 5.48 ~ 5.57 (100~80)7 ×1 4 6.45 ~ 6.51(100~85) 7 6.48 ~ 6.57 (100~80)8 ×1.25 5 7.31 ~ 7.38(100~85) 7 7.34 ~ 7.41 (100~85) 8 ×1 4 7.45 ~ 7.51(100~85) 7 7.48 ~ 7.57 (100~80) 10 ×1.5 5 9.16 ~ 9.22(100~90) 7 9.18 ~ 9.28 (100~85) 10 ×1.25 5 9.31 ~ 9.38(100~85) 7 9.34 ~ 9.41 (100~85) 10 ×1 5 9.46 ~ 9.52(100~85) 7 9.48 ~ 9.57 (100~80)12 ×1.75 5 11.01 ~11.08(100~90) 8 11.05 ~11.15(100~85)12 ×1.5 5 11.16 ~11.22(100~90) 7 11.18 ~11.28(100~85)12 ×1.25 5 11.31 ~11.38(100~85) 7 11.34 ~11.41(100~85)12 ×1 5 11.46 ~11.52(100~85) 7 11.48 ~11.57(100~80)14 ×2 6 12.83 ~12.95(100~90) 10 12.92 ~13.04(100~85)14 ×1.5 5 13.16 ~13.22(100~90) 9 13.21 ~13.30(100~85)16 ×2 6 14.87 ~14.95(100~90) 10 14.92 ~15.04(100~85)16 ×1.5 5 15.16 ~15.22(100~90) 9 15.21 ~15.30(100~80)18 ×2.5 6 16.57 ~16.67(100~90) 11 16.63 ~16.78(100~85)18 ×1.5 6 17.17 ~17.23(100~90) 10 17.22 ~17.31(100~85)20 ×2.5 6 18.57 ~18.67(100~90) 11 18.63 ~18.78(100~85)20 ×1.5 6 19.17 ~19.23(100~90) 10 19.22 ~19.31(100~85)9、美制粗牙螺紋(NRT) (單位：mm)螺紋尺寸2B級螺紋用下孔徑3B級螺紋用下孔徑RH 精度最小～最大(嵌合率％)RH精度最小～最大(嵌合率％)NO.2-56UNC 4 1.96 ~ 2.02 (100~65) 3 1.95 ~ 2.01 (100~65) 3-48 4 2.25 ~ 2.32 (100~65) 3 2.23 ~ 2.31 (100~65) 4-40 5 2.52 ~ 2.60 (100~70) 3 2.50 ~ 2.58 (100~70) 5-40 5 2.86 ~ 2.93 (100~70) 3 2.83 ~ 2.91 (100~70) 6-32 5 3.09 ~ 3.17 (100~75) 3 3.06 ~ 3.14 (100~75) 8-32 6 3.75 ~ 3.83 (100~75) 4 3.74 ~ 3.82 (100~75) 10-24 6 4.26 ~ 4.35 (100~80) 4 4.24 ~ 4.32 (100~80) 12-24 6 4.92 ~ 5.01 (100~80) 4 4.90 ~ 4.96 (100~85) 1/4 -20 6 5.66 ~ 5.76 (100~80) 4 5.64 ~ 5.74 (100~80) 5/16 -18 7 7.18 ~7.29 (100~80) 5 7.15 ~7.24 (100~85) 3/8 -16 7 8.66 ~8.78 (100~80) 5 8.63 ~8.73 (100~85)7/16 -14 7 10.11 ~10.25(100~80) 5 10.08 ~10.19 (100~85)1/2 -13 8 10.62 ~11.78(100~80) 6 11.60 ~11.68 (100~90)9/16 -12 10 13.14 ~13.27(100~85) 8 13.11 ~13.24 (100~85)5/8 -11 11 14.62 ~14.76(100~85) 8 14.58 ~14.67 (100~90)3/4 -10 12 17.67 ~17.88(100~80) 9 17.63 ~17.74 (100~90)7/8 - 9 12 20.68 ~20.85(100~85) 9 20.64 ~20.75 (100~90)1 - 8 13 23.65 ~23.84(100~85) 10 23.61 ~23.74 (100~90)二、螺紋下孔徑表(無屑絲攻用)1、美制細牙螺紋(NRT) (單位：mm)螺紋尺寸2B級螺紋用下孔徑3B級螺紋用下孔徑RH 精度最小～最大(嵌合率％)RH精度最小～最大(嵌合率％)NO.2-64UNF 3 1.98 ~ 2.04 (100~65) 2 1.97 ~ 2.03 (100~65) 3-56 4 2.29 ~ 2.35 (100~65) 3 2.28 ~ 2.34 (100~65)4-48 4 2.57 ~ 2.64 (100~70) 3 2.56 ~ 2.63 (100~70)5-44 4 2.88 ~ 2.95 (100~70) 3 2.87 ~ 2.94 (100~70)6-40 5 3.19 ~ 3.26 (100~70) 3 3.16 ~ 3.22 (100~75)8-36 5 3.80 ~ 3.88 (100~75) 4 3.79 ~ 3.86 (100~75) 10-32 5 4.41 ~ 4.48 (100~80) 4 4.40 ~ 4.46 (100~80) 12-28 5 5.00 ~ 5.08 (100~80) 4 4.99 ~ 5.06 (100~80) 1/4-28 5 5.86 ~ 5.93 (100~80) 4 5.85 ~ 5.92 (100~80) 5/16-24 6 7.38 ~7.46 (100~80) 5 7.36 ~7.43 (100~85) 3/8 -24 6 8.96 ~9.05 (100~80) 5 8.95 ~9.02 (100~85) 7/16-20 7 10.44 ~10.54 (100~80) 5 10.41 ~10.49 (100~85) 1/2-20 7 12.02 ~12.12 (100~80) 5 12.00 ~12.05 (100~90) 9/16-18 9 13.55 ~13.66 (100~80) 7 13.53 ~13.58 (100~90) 5/8 -18 9 15.14 ~15.25 (100~80) 7 15.11 ~15.17 (100~90) 3/4 -16 10 18.22 ~18.32 (100~85) 7 18.18 ~18.25 (100~90) 7/8 -14 11 21.27 ~21.38 (100~85) 8 21.23 ~21.27 (100~95)1 - 12 12 24.28 ~24.41 (100~85) 9 24.24 ~24.32 (100~90)2、英制管用平行螺紋(NRT) (單位：mm)螺紋尺寸RH精度最小～最大(嵌合率％)PF 1/8 6 9.24~9.35 (100~80)1/4 7 12.41~12.62 (100~75)3/8 7 15.92~16.12 (100~75)1/2 8 19.93~20.15 (100~80)3/4 8 25.41~25.64 (100~80)3、公制螺紋(HRT) (單位：mm)螺紋尺寸1級螺紋用下孔徑2級螺紋用下孔徑RH 精度最小～最大(嵌合率％)RH精度最小～最大(嵌合率％)M 1×0.25 2 0.858~0.879(100~85)4 0.858~0.887 (100~80)1.2×0.25 2 1.058~1.079(100~85)4 1.058~1.087 (100~80) 1.4×0.3 2 1.23 ~1.26 (100~85) 4 1.23 ~1.26 (100~80) 1.6×0.35 2 1.40 ~1.44 (100~80) 4 1.40 ~1.45 (100~75) 1.7×0.35 －1.50 ~1.54 (100~80) 4 1.50 ~1.55 (100~75)1.8×0.35 2 1.60 ~1.64 (100~80) 4 1.60 ~1.65 (100~75)2 ×0.4 2 1.77 ~1.82 (100~80) 4 1.77 ~1.82 (100~80) 2 ×0.25 2 1.858~1.887(100~80)－1.858~1.887 (100~80) 2.3×0.4 － 2.07 ~2.12 (100~80) 4 2.07 ~2.13 (100~75) 2.5×0.45 3 2.24 ~2.30 (100~80) 5 2.24 ~2.31 (100~75)2.6×0.45 － 2.34 ~2.40 (100~80) 5 2.34 ~2.41 (100~75)3 ×0.6 3 2.72 ~2.73 (100~90) 5 2.66 ~2.73 (100~90) 3 ×0.5 52.72 ~2.77 (100~80) 6 2.72 ~2.78 (100~75)3 ×0.35 3 2.80 ~2.84 (100~80)5 2.80 ~2.85 (100~75)3.5×0.6 3 3.16 ~3.21 (100~85) 5 3.16 ~3.25 (100~75)4 ×0.75 3 3.57 ~3.64 (100~85)6 3.57 ~3.64 (100~85) 4 ×0.7 6 3.60 ~3.66 (100~85) 7 3.60 ~3.66 (100~85)4 ×0.5 3 3.71 ~3.77 (100~80)6 3.71 ~3.79 (100~75)5 ×0.9 3 4.49 ~4.59 (100~85) 7 4.49 ~4.59 (100~85) 5 ×0.8 34.55 ~4.62 (100~85) 8 4.55 ~4.64 (100~80)5 ×0.5 3 2.72 ~4.77 (100~80)6 4.72 ~4.79 (100~75)6 ×1 4 5.43 ~5.52 (100~85)7 5.43 ~5.55 (100~80) 6 ×0.75 3 5.57 ~5.64 (100~85) 7 5.57 ~5.66 (100~80)4、公制粗牙螺紋HL-NRT (單位：mm)螺紋尺寸RH精度最小～最大(嵌合率％) M 3 ×0.5 3 3.39~3.43 (100~80)4 ×0.7 4 4.54~4.58 (100~85)5 ×0.8 4 5.61~5.66 (100~85)6 ×1 4 6.75~6.81 (100~85) 8 ×1.25 5 8.93~9.01 (100~85) 10 ×1.5 5 11.11~11.17 (100~90) 10 ×1.25 5 10.93~11.01 (100~85) 12 ×1.75 5 13.28~13.17 (100~90) 12 ×1.5 5 13.11~13.17 (100~90) 12 ×1.255 12.93~13.01 (100~85)三、螺紋下孔徑表(護套螺紋用)螺紋尺寸下孔徑鑽頭直徑最小直徑最大直徑M 2.5×0.45 2.60 2.65 2.62.6×0.45 2.70 2.75 2.73 ×0.5 3.12 3.20 3.14 ×0.7 4.17 4.30 4.25 ×0.8 5.16 5.33 5.26 ×1 6.25 6.42 6.3 8 ×1.25 8.31 8.52 8.4 10 ×1.5 10.37 10.62 10.5 12 ×1.75 12.43 12.73 12.514 ×2 14.49 14.83 14.5 16 ×2 16.49 16.83 16.5 18 ×2.5 18.58 19.04 19.0 20 ×2.5 20.58 21.04 21.0 22 ×2.5 22.58 23.04 23.0 24 ×2.5 24.70 25.25 25.02、公制細牙螺紋(單位：mm)螺紋尺寸下孔徑鑽頭直徑最小直徑最大直徑M 10 ×1 10.25 10.42 10.310 ×1.25 10.31 10.52 10.412 ×1.25 12.31 12.52 12.512 ×1.5 12.37 12.62 12.514 ×1.5 14.37 14.62 14.516 ×1.5 16.37 16.62 16.518 ×1.5 18.37 18.62 18.520 ×1.5 20.37 20.62 20.520 ×2 20.47 20.83 20.522 ×1.5 22.37 22.62 22.524 ×1.5 24.37 24.62 24.524 ×2 24.47 24.83 24.530 ×1.5 30.37 30.62 30.5螺紋尺寸下孔徑鑽頭直徑最小直徑最大直徑NO. 2 –56UNC 2.29 2.39 2.33 –48 2.64 2.74 2.74 –40 2.95 3.07 3.05 –40 3.25 3.38 3.36 –32 3.66 3.81 3.78 –32 4.32 4.47 4.410 –24 5.05 5.21 5.112 –24 5.61 5.77 5.71/4 –20 6.63 6.78 6.75/16 –8 8.33 8.48 8.43/8 –16 9.91 10.11 10.07/16–14 11.51 11.76 11.51/2 –13 13.08 13.34 13.19/16–12 14.68 14.94 14.74、美制細牙螺紋(單位：mm)螺紋尺寸下孔徑鑽頭直徑最小直徑最大直徑NO. 4 –48UNF 2.97 3.05 3.06 –40 3.66 3.78 3.78 –36 4.32 4.44 4.410 –32 4.98 5.13 5.01/4 –28 6.53 6.71 6.6 5/16 –24 8.20 8.38 8.23/8 –24 9.78 9.96 9.8 7/16 –20 11.43 11.63 11.51/2 –20 13.03 13.26 13.1 9/16 –18 14.66 14.88 14.7 5/8 –18 16.26 16.48 16.33/4 –16 19.43 19.68 19.57/8 –14 22.61 22.86 22.71 –12 25.76 26.04 26.0各種換算表管用螺絲基準寸法(mm)規格英制JIS(PT)美式ASA(NPT)山數外徑有效徑山數外徑有效徑1/167.723277.777.142 1/8289.7289.1472710.1169.4891/41913.15712.3011813.42712.4873/81916.66215.8061816.86615.9261/21420.95519.7931420.98019.7723/41426.44125.2791426.32625.11711133.24931.770111/233.93231.46111/41141.91040.431111/241.68940.21811/21147.80346.324111/247.68946.28721159.61458.135111/259.79658.32521/21175.18473.705872.27370.15931187.88486.405888.18286.06831/211100.33098.8518100.69198.776411113.030111.5518113.548111.433 41/211125.730124.251 511138.430136.9518141.3138.412 51/211151.130149.651611163.830162.3518168.3165.252 711189.230187.751811214.630213.1518219.1215.901美制螺絲外徑公厘(mm)換算表規格吋mmNO.00.0600 1.52410.0730 1.85420.0860 2.18430.0990 2.51540.1120 2.84550.1250 3.17560.1380 3.50580.1640 4.166100.1900 4.826120.2160 5.486山數節距換算表山數(每25.4mm) 節距mm100 0.254080 0.317572 0.352864 0.3969 60 0.4233 56 0.4536 48 0.5292 44 0.5773 40 0.6350 36 0.7056 32 0.7938 28 0.9071 24 1.0583 20 1.2700 18 1.4111 16 1.5875 14 1.8143 13 1.9538 12 2.1167 11 2.3091 10 2.54009 2.82228 3.17507 3.62866 4.23335 5.0800 4 1/2 5.64444 6.3500 3 1/2 7.2571 3 1/4 7.81543 8.4667 2 7/8 8.8348 2 3/4 9.2364 2 5/8 9.6762 2 1/2 10.1600。

攻牙底孔的使用参数表一、螺紋下孔徑表1、公制粗牙螺紋JIS B 0209-1982(單位: mm)2、公制細牙螺紋-01mm)公制細牙螺紋-02 JIS B 0211-1982(單位: mm)註⑴等級：6H⑵基於JIS B 0211-1982標準3、美制粗牙螺紋（單位：mm）4、美制細牙螺紋5、英制粗牙螺紋 （單位：mm ）（單位：mm ）6、英制管用螺紋（單位：mm）7、美制管用耐密斜行螺紋（NPTF取PSF）（單位：mm）上述鑽頭直徑來源於美制管用耐密斜行螺紋ANSI B1.20.3 —1957 Dryseal Pipe Threads （Inch）標準8、公制螺紋（NRT）（單位：mm）9、美制粗牙螺紋（NRT）（單位：二、螺紋下孔徑表（無屑絲攻用）1、美制細牙螺紋（NRT）（單位：mm）（HRT）（mm）34、公制粗牙螺紋HL-NRT （單位：mm）三、螺紋下孔徑表（護套螺紋用）1、公制粗牙螺紋（單位：mm）12 X 1.75 12.43 12.73 12.5 14 X 214.4914.8314.5 16 X 2 16.49 16.83 16.5 18 X 2.5 18.58 19.0419.0 20 X 2.5 20.58 21.04 21.0 22 X 2.522.58 23.0423.0 24 X 2.524.7025.2525.0螺紋尺寸下孑L 徑鑽頭直徑|最小直徑 |最大直徑M 10 X 1 10.25 10.42 10.3 10 X 1.25L 10.31 J10.5210.4 12 X 1.25 12.31 12.52 12.5 12 X 1.5L 12.37 」 12.6212.5 14 X 1.5 14.37 14.62 14.5 16 X 1.5L 16.37J16.6216.5 18 X 1.5 18.3718.62 18.5 20 X 1.5匚 20.37J 20.6220.5 20 X 2 20.47 20.83 20.5 22 X 1.5L 22.37 」 22.6222.5 24 X 1.5 24.37 24.62 24.5 24 X 2L 24.47J24.8324.5 30 X 1.530.3730.6230.52、公制細牙螺紋 螺紋尺寸下孑L 徑鑽頭直徑J|最小直徑| NO. 2 - 56UNC 2.29 2.392.3 3 - 482.642.74 2.7 4 - 40 2.953.07 3.0 5 - 403.25 13.38 3.3 | 6 - 32 3.66 3.81 3.7 8 - 32L 4.32 」L 4.47 4.4 110 — 24 5.05 5.21 5.1 12 — 245.61 1 5.77 57 1 1/4 — 206.63 6.78 6.7 5/16 - 88.33 18.48 8.4 3/8 - 16 9.91 10.11 10.0 3、美制粗牙螺紋（單位：mm ）mm)（mm）4各種換算表管用螺絲基準寸法（mm）美制螺絲外徑公厘（mm）換算表山數節距換算表。

攻牙底孔的使用参数表一、螺紋下孔徑表1、公制粗牙螺紋JIS B 0209-1982(單位：mm)螺纹尺寸钻头直径螺纹下孔徑內螺紋小徑最小直径最大直径M 1 ×0.25 0.75 0.78 (80%) 0.729 0.7851.1 ×0.25 0.85 0.88 (80%) 0.829 0.8851.2 ×0.25 0.95 0.98 (80%) 0.929 0.9851.4 ×0.3 1.1 1.14 (80%) 1.075 1.1421.6 ×0.35 1.25 1.32 (75%) 1.221 1.3211.8 ×0.35 1.45 1.52 (75%) 1.421 1.5212 ×0.4 1.6 1.65 (80%) 1.567 1.6792.2 ×0.45 1.75 1.83 (75%) 1.713 1.8382.5 ×0.45 2.1 2.13 (75%) 2.013 2.1383 ×0.5 2.5 2.59 (75%) 2.459 2.5993.5 ×0.6 2.9 3.01 (75%) 2.850 3.0104 ×0.7 3.3 3.39 (80%) 3.242 3.4224.5 ×0.75 3.8 3.85 (80%) 3.688 3.8785 ×0.8 4.2 4.31 (80%) 4.134 4.3346 × 1 5 5.13 (80%) 4.917 5.1537 × 1 6 6.13 (80%) 5.917 6.1538 × 1.25 6.8 6.85 (85%) 6.647 6.9129 × 1.25 7.8 7.85 (85%) 7.647 7.91210 × 1.5 8.5 8.62 (85%) 8.376 8.67611 × 1.5 9.5 9.62 (85%) 9.376 9.67612 × 1.75 10.3 10.40 (85%) 10.106 10.44114 × 2 12 12.2 (85%) 11.835 12.21016 × 2 14 14.2 (85%) 13.835 14.21018 × 2.5 15.5 15.7 (85%) 15.294 15.74420 × 2.5 17.5 17.7 (85%) 17.294 17.74422 × 2.5 19.5 19.2 (85%) 19.294 19.74424 × 3 21 21.2 (85%) 20.752 21.25227 × 3 24 24.2 (85%) 23.752 24.25230 × 3.5 26.5 26.6 (90%) 26.211 26.77133 × 3.5 29.5 29.6 (90%) 29.211 29.77136 × 4 32 32.1 (90%) 31.670 32.27039 × 4 35 35.1 (90%) 34.670 35.27042 × 4.5 37.5 37.6 (90%) 37.129 37.79945 × 4.5 40.5 40.6 (90%) 40.129 40.79948 × 5 43 43.1 (90%) 42.587 43.297 註(1)M1.4以下等級：5H、M1.6以上等級：6H (2)基於JIS B 0209-1982標準2、公制細牙螺紋-01 JIS B 0211-1982(單位：mm)螺纹尺寸钻头直径螺纹下孔徑內螺紋小徑最小直径最大直径M 2.5 ×0.35 2.2 2.22 (75%) 2.121 2.2213 ×0.35 2.7 2.72 (75%) 2.621 2.7213.5 ×0.35 3.2 3.22 (75%) 3.121 3.2214 ×0.5 3.5 3.59 (75%) 3.459 3.5994.5 ×0.5 4 4.09 (75%) 3.959 4.0995 ×0.5 4.5 4.59 (75%) 4.459 4.5995.5 ×0.5 5 5.09 (75%) 4.959 5.0996 ×0.75 5.3 5.35 (80%) 5.188 5.3787 ×0.75 6.3 6.35 (80%) 6.188 6.3788 × 1 7 7.13 (80%) 6.917 7.1538 ×0.75 7.3 7.35 (80%) 7.188 7.3789 × 1 8 8.13 (80%) 7.917 8.1539 ×0.75 8.3 8.35 (80%) 8.188 8.37810 × 1.25 8.8 8.85 (85%) 8.647 8.91210 × 1 9 9.13 (80%) 8.917 9.15310 ×0.75 9.3 9.35 (80%) 9.188 9.37811 × 1 10 10.13 (80%) 9.917 10.15311 ×0.75 10.3 10.35 (80%) 10.188 10.37812 × 1.5 10.5 10.62 (85%) 10.376 10.67612 × 1.25 10.8 10.85 (85%) 10.647 10.91212 × 1 11 11.13 (80%) 10.917 11.15314 × 1.5 12.5 12.62 (85%) 12.376 12.67614 × 1 13 13.13 (80%) 12.917 13.15315 × 1.5 13.5 13.62 (85%) 13.376 13.67615 × 1 14 14.13 (80%) 13.917 14.15316 × 1.5 14.5 14.62 (85%) 14.376 14.67616 × 1 15 15.13 (80%) 14.917 15.15317 × 1.5 15.5 15.62 (85%) 15.376 15.67617 × 1 16 16.13 (80%) 15.917 16.15318 × 2 16 16.2 (85%) 15.835 16.21018 × 1.5 16.5 16.62 (85%) 16.376 16.67618 × 1 17 17.13 (80%) 16.917 17.15320 × 2 18 18.2 (85%) 17.835 18.21020 × 1.5 18.5 18.62 (85%) 18.376 18.67620 × 1 19 19.13 (80%) 18.917 19.15322 × 2 20 20.2 (85%) 19.835 20.21022 × 1.5 20.5 20.62 (85%) 20.376 20.67622 × 1 21 21.13 (80%) 20.917 21.15324 × 2 22 22.2 (85%) 21.835 22.21024 × 1.5 22.5 22.62 (85%) 22.376 22.67624 × 1 23 23.13 (80%) 22.917 23.15325 × 2 23 23.2 (85%) 22.835 23.21025 × 1.5 23.5 23.62 (85%) 23.376 23.67625 × 1 24 24.13 (80%) 23.917 24.153公制細牙螺紋-02 JIS B 0211-1982(單位：mm)螺纹尺寸钻头直径螺纹下孔徑內螺紋小徑最小直径最大直径M 26 × 1.5 24.5 24.62 (85%) 24.376 24.676 27 × 2 25 25.2 (85%) 24.835 25.210 27 × 1.5 25.5 25.62 (85%) 25.376 25.67627 × 1 26 26.13 (80%) 25.917 26.15328 × 2 26 26.2 (85%) 25.835 26.210 28 × 1.5 26.5 26.62 (85%) 26.376 26.676 28 × 1 27 27.13 (80%) 26.917 27.15330 × 3 27 27.2 (85%) 26.752 27.252 30 × 2 28 28.2 (85%) 27.835 28.210 30 × 1.5 28.5 28.62 (85%) 28.376 28.676 30 × 1 29 29.13 (80%) 28.917 29.153 32 × 2 30 30.2 (85%) 29.835 30.21032 × 1.5 30.5 30.62 (85%) 30.376 30.67633 × 3 30 30.2 (85%) 29.752 30.252 33 × 2 31 31.2 (85%) 30.835 31.210 33 × 1.5 31.5 31.62 (85%) 31.376 31.67635 × 1.5 33.5 33.62 (85%) 33.376 33.67636 × 3 33 33.2 (85%) 32.752 33.252 36 × 2 34 34.2 (85%) 33.835 34.210 36 × 1.5 34.5 34.62 (85%) 34.376 34.67638 × 1.5 36.5 36.62 (85%) 36.376 36.67639 × 3 36 36.2 (85%) 35.752 36.252 39 × 2 37 37.2 (85%) 36.835 37.21039 × 1.5 37.5 37.62 (85%) 37.376 37.67640 × 3 37 37.2 (85%) 36.752 37.252 40 × 2 38 38.2 (85%) 37.835 38.210 40 × 1.5 38.5 38.62 (85%) 38.376 38.676 42 × 4 38 38.1 (90%) 37.670 38.270 42 × 3 39 39.2 (85%) 38.752 39.252 42 × 2 40 40.2 (85%) 39.835 40.210 42 × 1.5 40.5 40.62 (85%) 40.376 40.676 45 × 4 41 41.1 (90%) 40.670 41.270 45 × 3 42 42.2 (85%) 41.752 42.252 45 × 2 43 43.2 (85%) 42.835 43.210 45 × 1.5 43.5 43.62 (85%) 43.376 43.676 48 × 4 44 44.1 (90%) 43.670 44.270 48 × 3 45 45.2 (85%) 44.752 45.252 48 × 2 46 46.2 (85%) 45.835 46.21048 × 1.5 46.5 46.62 (85%) 46.376 46.676 50 × 3 47 47.2 (85%) 46.752 47.252 50 × 2 48 48.2 (85%) 47.835 48.210 50 × 1.5 48.5 48.62 (85%) 48.376 48.676 註(1)等級：6H(2)基於JIS B 0211-1982標準3、美制粗牙螺紋(單位：mm)螺纹尺寸钻头直径2B级螺纹下孔徑內螺紋小徑最小直径最大直径NO.1 -64UNC 1.55 1.57 (65%) 1.425 1.5822 -56 1.8 1.86 (65%) 1.695 1.8713 -48 2.1 2.14 (65%) 1.941 2.1464 -40 2.3 2.36 (70%) 2.157 2.3855 -40 2.6 2.69 (70%) 2.487 2.6976 -32 2.8 2.86 (75%) 2.642 2.8958 -32 3.4 3.52 (75%) 3.302 3.530 10 -24 3.9 3.91 (80%) 3.683 3.962 12 -24 4.5 4.57 (80%) 4.344 4.5971/4 -20 5.1 5.25 (80%) 4.979 5.2575/16 -18 6.6 6.72 (80%) 6.401 6.7313/8 -16 8 8.15 (80%) 7.798 8.153 7/16 -14 9.4 9.50 (80%) 9.144 9.550 1/2 -13 10.8 11.0 (80%) 10.592 11.023 9/16 -12 12.2 12.3 (85%) 11.989 12.446 5/8 -11 13.6 13.8 (85%) 13.386 13.868 3/4 -10 16.5 16.8 (80%) 16.307 16.840 7/8 - 9 19.5 19.6 (85%) 19.177 19.761 1 - 8 22.2 22.5 (85%) 21.971 22.6061 1/8 - 7 25 25.2 (85%) 24.638 25.3491 1/4 - 7 28.2 28.4 (85%) 27.813 28.5241 3/8 - 6 30.8 31.0 (85%) 30.353 31.1151 1/2 - 6 34 34.2 (85%) 33.528 34.2901 3/4 - 5 39.5 39.8 (85%) 38.964 39.8272 - 4 45.2 45.3 (90%) 44.679 45.593 4、美制細牙螺紋(單位：mm)螺纹尺寸钻头直径2B级螺纹下孔徑內螺紋小徑最小直径最大直径NO. 0 -80UNF 1.25 1.30 (65%) 1.182 1.3051 -72 1.55 1.61 (65%) 1.474 1.6122 -64 1.85 1.90 (65%) 1.756 1.9123 -56 2.1 2.17 (70%) 2.025 2.1974 -48 2.4 2.44 (70%) 2.271 2.4585 -44 2.7 2.74 (70%) 2.551 2.7406 -40 2.9 3.02 (70%) 2.820 3.0228 -36 3.5 3.59 (75%) 3.404 3.60610 -32 4.1 4.14 (80%) 3.963 4.16512 -28 4.6 4.70 (80%) 4.496 4.7241/4 -28 5.5 5.56 (80%) 5.360 5.5885/16 -24 6.9 7.02 (80%) 6.782 7.0353/8 -24 8.5 8.61 (80%) 8.382 8.6367/16 -20 9.9 10.01 (80%) 9.729 10.033 1/2 -20 11.5 11.60 (80%) 11.329 11.607 9/16 -18 12.9 13.07 (80%) 12.751 13.081 5/8 -18 14.5 14.65 (80%) 14.351 14.681 3/4 -16 17.5 17.59 (85%) 17.323 17.678 7/8 -14 20.5 20.6 (85%) 20.270 20.675 1 -12 23.2 23.5 (85%) 23.114 23.571 1 1/8 -12 26.5 26.7 (80%) 26.289 26.746 1 1/4 -12 29.5 29.9 (80%) 29.464 29.921 1 3/8 -12 32.8 33.0 (85%) 32.639 33.096 1 1/2 -12 36 36.2 (85%) 35.814 36.271 5、英制粗牙螺紋(單位：mm) 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W 1/8 2.6 2.5 70.7 83.0 70.0 88.3 3/16 3.7 3.6 78.4 85.8 70.0 88.3 1/4 5.1 5.0 76.9 83.0 70.5 88.3 5/16 6.6 6.5 74.0 99.5 70.1 88.4 3/8 8.0 7.9 75.0 80.0 69.5 88.2 7/16 9.4 9.3 73.7 80.0 69.0 88.8 1/2 10.7 10.5 73.8 81.2 69.0 88.2 9/16 12.3 12.0 73.4 84.4 69.0 88.2 5/8 13.7 13.5 73.5 80.3 69.6 88.5 3/4 16.7 16.5 72.3 78.4 69.6 88.3 7/8 19.5 19.3 75.4 80.9 70.1 88.4 1 22.4 22.0 73.8 83.6 71.0 88.2 1 1/8 25.0 24.8 76.9 81.3 72.0 88.4 1 1/4 28.3 28.0 74.3 80.7 72.0 88.4 1 3/8 30.5 30.3 81.6 85.3 73.8 88.6 1 1/2 33.8 33.5 79.3 84.8 73.8 88.6 1 5/8 36.0 35.7 81.1 85.7 74.8 88.3 1 3/4 39.2 39.0 80.7 83.8 74.8 88.31 7/8 41.8 41.5 80.6 84.7 74.7 88.42 45.0 44.7 80.2 84.4 74.7 88.4 6、英制管用螺紋(單位：mm)管用螺紋尺寸JIS B 0203 JIS B 2301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1/16 6.230 6.2 6.490 6.5 －－1/8 8.235 8.2 8.495 8.5 8.191 8.2 1/4 10.941 10.9 11.341 11.4 10.945 10.9 3/8 14.428 14.4 14.846 14.9 14.388 14.4 1/2 17.950 18 18.489 18.5 17.943 18 3/4 23.349 23 23.975 24 23.305 23 1 29.423 29 30.111 30 29.353 29 1 1/4 37.940 38 38.772 39 37.890 381 1/2 43.833 44 44.565 45 43.720 432 55.412 55 56.476 56 55.406 552 1/2 70.701 71 72.009 72 70.788 703 83.201 83 84.709 85 83.364 833 1/2 95.547 96 97.155 97 95.747 954 107.834 108 109.855 110 108.322 1085 133.110 133 135.255 135 133.597 1336 158.510 159 160.655 161 158.810 1587 183.360 183 185.954 1868 208.560 209 211.354 2129 233.960 234 236.754 23710 259.166 259 262.154 26212 309.747 310 312.875 3137、美制管用耐密斜行螺紋(NPTF‧NPSF) (單位：mm)管用螺紋尺寸斜行螺紋(NPTF) 平行螺紋(NPSF)鑽頭直徑鑽頭直徑使用鉸刀場合不使用鉸刀合1/16 －0.234 ( 5.94) 0.246 ( 6.25) 1/4 0.250 ( 6.35) 1/8 21/64 0.328 ( 8.33) 0.339 ( 8.61) 11/32 0.344 ( 8.74)1/4 27/64 0.422 (10.72) 7/16 0.438 (11.13) －0.444 (11.28) 3/8 9/16 0.562 (14.27) 37/64 0.578 (14.68) 37/64 0.578 (14.68) 1/2 11/16 0.688 (17.48) 45/64 0.703 (17.86) 23/32 0.719 (18.26) 3/4 57/64 0.891 (22.63) 59/64 0.922 (23.42) －0.922 (23.42) 1 1 1/8 1.125 (28.58) 1 5/32 1.156 (29.36) 1 5/32 1.156 (29.36) 1 1/4 1 15/32 1.469 (37.31) 11/21.500 (38.10) －－1 1/2 1 45/64 1.703 (43.26) 147/641.734 (44.04) －－2 2 3/16 2.188 (55.58) 2 7/32 2.219 (56.36) －－2 1/2 2 19/32 2.594 (65.89) 241/642.641 (67.08) －－上述鑽頭直徑來源於美制管用耐密斜行螺紋ANSI B1.20.3—1957 Dryseal Pipe Threads (Inch)標準8、公制螺紋(NRT) (單位：mm)螺紋尺寸1級螺紋用下孔徑2級螺紋用下孔徑RH 精度最小～最大(嵌合率％)RH精度最小～最大(嵌合率％)M 1 ×0.25 2 0.87 ~ 0.89 (100~85) 4 0.90 ~0.92 (100~80) 1.1×0.25 2 0.97 ~ 0.99 (100~85) 4 1.00 ~1.02 (100~80) 1.2×0.25 2 1.07 ~ 1.09 (100~85) 4 1.10 ~1.12 (100~80) 1.4×0.3 2 1.244~ 1.263 (100~85) 4 1.270~ 1.294 (100~80)1.7×0.35 2 1.51 ~ 1.54 (100~80) 4 1.54 ~ 1.58 (100~75)2 ×0.4 2 1.78 ~ 1.82 (100~80) 4 1.81 ~ 1.85 (100~75) 2.3×0.4 2 2.08 ~ 2.12 (100~80) 4 2.11 ~ 2.15 (100~75) 2.5×0.45 2 2.25 ~ 2.29 (100~80) 4 2.28 ~ 2.33 (100~75)2.6×0.45 2 2.35 ~ 2.39 (100~80) 4 2.38 ~ 2.43 (100~75)3 ×0.5 3 2.74 ~ 2.78 (100~80)5 2.76 ~ 2.81 (100~75)3.5×0.6 3 3.18 ~ 3.21 (100~85) 5 3.20 ~ 3.26 (100~75)4 ×0.7 4 3.63 ~ 3.67 (100~85) 6 3.65 ~ 3.70 (100~85)5 ×0.8 4 4.57 ~ 4.62 (100~85)6 4.59 ~ 4.66 (100~80)6 ×1 4 5.45 ~ 5.51 (100~85)7 5.48 ~ 5.57 (100~80)7 ×1 4 6.45 ~ 6.51 (100~85) 7 6.48 ~ 6.57 (100~80)8 ×1.25 5 7.31 ~ 7.38 (100~85) 7 7.34 ~ 7.41 (100~85) 8 ×1 4 7.45 ~ 7.51 (100~85) 7 7.48 ~ 7.57 (100~80) 10 ×1.5 5 9.16 ~ 9.22 (100~90) 7 9.18 ~ 9.28 (100~85) 10 ×1.25 5 9.31 ~ 9.38 (100~85) 7 9.34 ~ 9.41 (100~85) 10 ×1 5 9.46 ~ 9.52 (100~85) 7 9.48 ~ 9.57 (100~80) 12 ×1.75 5 11.01 ~11.08 (100~90) 8 11.05 ~11.15 (100~85) 12 ×1.5 5 11.16 ~11.22 (100~90) 7 11.18 ~11.28 (100~85) 12 ×1.25 5 11.31 ~11.38 (100~85) 7 11.34 ~11.41 (100~85) 12 ×1 5 11.46 ~11.52 (100~85) 7 11.48 ~11.57 (100~80) 14 ×2 6 12.83 ~12.95 (100~90) 10 12.92 ~13.04 (100~85) 14 ×1.5 5 13.16 ~13.22 (100~90) 9 13.21 ~13.30 (100~85) 16 ×2 6 14.87 ~14.95 (100~90) 10 14.92 ~15.04 (100~85) 16 ×1.5 5 15.16 ~15.22 (100~90) 9 15.21 ~15.30 (100~80) 18 ×2.5 6 16.57 ~16.67 (100~90) 11 16.63 ~16.78 (100~85) 18 ×1.5 6 17.17 ~17.23 (100~90) 10 17.22 ~17.31 (100~85) 20 ×2.5 6 18.57 ~18.67 (100~90) 11 18.63 ~18.78 (100~85) 20 ×1.5 6 19.17 ~19.23 (100~90) 10 19.22 ~19.31 (100~85) 9、美制粗牙螺紋(NRT) (單位：mm)螺紋尺寸2B級螺紋用下孔徑3B級螺紋用下孔徑RH 最小～最大RH 最小～最大精度(嵌合率％) 精度(嵌合率％)NO. 2-56UNC 4 1.96 ~ 2.02 (100~65) 3 1.95 ~ 2.01 (100~65) 3-48 4 2.25 ~ 2.32 (100~65) 3 2.23 ~ 2.31 (100~65) 4-40 5 2.52 ~ 2.60 (100~70) 3 2.50 ~ 2.58 (100~70) 5-40 5 2.86 ~ 2.93 (100~70) 3 2.83 ~ 2.91 (100~70) 6-32 5 3.09 ~ 3.17 (100~75) 3 3.06 ~ 3.14 (100~75) 8-32 6 3.75 ~ 3.83 (100~75) 4 3.74 ~ 3.82 (100~75) 10-24 6 4.26 ~ 4.35 (100~80) 4 4.24 ~ 4.32 (100~80) 12-24 6 4.92 ~ 5.01 (100~80) 4 4.90 ~ 4.96 (100~85) 1/4 -20 6 5.66 ~ 5.76 (100~80) 4 5.64 ~ 5.74 (100~80) 5/16 -18 7 7.18 ~ 7.29 (100~80) 5 7.15 ~ 7.24 (100~85) 3/8 -16 7 8.66 ~ 8.78 (100~80) 5 8.63 ~ 8.73 (100~85) 7/16 -14 7 10.11 ~10.25 (100~80) 5 10.08 ~10.19 (100~85) 1/2 -13 8 10.62 ~11.78 (100~80) 6 11.60 ~11.68 (100~90) 9/16 -12 10 13.14 ~13.27 (100~85) 8 13.11 ~13.24 (100~85) 5/8 -11 11 14.62 ~14.76 (100~85) 8 14.58 ~14.67 (100~90) 3/4 -10 12 17.67 ~17.88 (100~80) 9 17.63 ~17.74 (100~90) 7/8 - 9 12 20.68 ~20.85 (100~85) 9 20.64 ~20.75 (100~90)1 - 8 13 23.65 ~23.84 (100~85) 10 23.61 ~23.74 (100~90)二、螺紋下孔徑表(無屑絲攻用)1、美制細牙螺紋(NRT) (單位：mm)螺紋尺寸2B級螺紋用下孔徑3B級螺紋用下孔徑RH 精度最小～最大(嵌合率％)RH精度最小～最大(嵌合率％)NO. 2-64UNF 3 1.98 ~ 2.04 (100~65) 2 1.97 ~ 2.03 (100~65) 3-56 4 2.29 ~ 2.35 (100~65) 3 2.28 ~ 2.34 (100~65) 4-48 4 2.57 ~ 2.64 (100~70) 3 2.56 ~ 2.63 (100~70) 5-44 4 2.88 ~ 2.95 (100~70) 3 2.87 ~ 2.94 (100~70) 6-40 5 3.19 ~ 3.26 (100~70) 3 3.16 ~ 3.22 (100~75) 8-36 5 3.80 ~ 3.88 (100~75) 4 3.79 ~ 3.86 (100~75) 10-32 5 4.41 ~ 4.48 (100~80) 4 4.40 ~ 4.46 (100~80) 12-28 5 5.00 ~ 5.08 (100~80) 4 4.99 ~ 5.06 (100~80) 1/4 -28 5 5.86 ~ 5.93 (100~80) 4 5.85 ~ 5.92 (100~80) 5/16-24 6 7.38 ~ 7.46 (100~80) 5 7.36 ~ 7.43 (100~85) 3/8 -24 6 8.96 ~ 9.05 (100~80) 5 8.95 ~ 9.02 (100~85) 7/16-20 7 10.44 ~10.54 (100~80) 5 10.41 ~10.49 (100~85) 1/2 -20 7 12.02 ~12.12 (100~80) 5 12.00 ~12.05 (100~90) 9/16-18 9 13.55 ~13.66 (100~80) 7 13.53 ~13.58 (100~90) 5/8 -18 9 15.14 ~15.25 (100~80) 7 15.11 ~15.17 (100~90) 3/4 -16 10 18.22 ~18.32 (100~85) 7 18.18 ~18.25 (100~90) 7/8 -14 11 21.27 ~21.38 (100~85) 8 21.23 ~21.27 (100~95)1 - 12 12 24.28 ~24.41 (100~85) 9 24.24 ~24.32 (100~90)2、英制管用平行螺紋(NRT) (單位：mm)螺紋尺寸RH精度最小～最大(嵌合率％)PF 1/8 6 9.24~ 9.35 (100~80)1/4 7 12.41~12.62 (100~75)3/8 7 15.92~16.12 (100~75)1/2 8 19.93~20.15 (100~80)3/4 8 25.41~25.64 (100~80)3、公制螺紋(HRT) (單位：mm)螺紋尺寸1級螺紋用下孔徑2級螺紋用下孔徑RH 精度最小～最大(嵌合率％)RH精度最小～最大(嵌合率％)M 1 ×0.25 2 0.858~0.879 (100~85) 4 0.858~0.887 (100~80) 1.2×0.25 2 1.058~1.079 (100~85) 4 1.058~1.087 (100~80) 1.4×0.3 2 1.23 ~1.26 (100~85) 4 1.23 ~1.26 (100~80) 1.6×0.35 2 1.40 ~1.44 (100~80) 4 1.40 ~1.45 (100~75) 1.7×0.35 － 1.50 ~1.54 (100~80) 4 1.50 ~1.55 (100~75)1.8×0.35 2 1.60 ~1.64 (100~80) 4 1.60 ~1.65 (100~75)2 ×0.4 2 1.77 ~1.82 (100~80) 4 1.77 ~1.82 (100~80) 2 ×0.25 2 1.858~1.887 (100~80) － 1.858~1.887 (100~80) 2.3×0.4 － 2.07 ~2.12 (100~80) 4 2.07 ~2.13 (100~75) 2.5×0.45 3 2.24 ~2.30 (100~80)5 2.24 ~2.31 (100~75)2.6×0.45 － 2.34 ~2.40 (100~80) 5 2.34 ~2.41 (100~75)3 ×0.6 3 2.72 ~2.73 (100~90) 5 2.66 ~2.73 (100~90) 3 ×0.5 5 2.72 ~2.77 (100~80) 6 2.72 ~2.78 (100~75) 3 ×0.35 3 2.80 ~2.84 (100~80)5 2.80 ~2.85 (100~75)3.5×0.6 3 3.16 ~3.21 (100~85) 5 3.16 ~3.25 (100~75)4 ×0.75 3 3.57 ~3.64 (100~85)6 3.57 ~3.64 (100~85) 4 ×0.7 6 3.60 ~3.66 (100~85) 7 3.60 ~3.66 (100~85)4 ×0.5 3 3.71 ~3.77 (100~80)6 3.71 ~3.79 (100~75)5 ×0.9 3 4.49 ~4.59 (100~85) 7 4.49 ~4.59 (100~85) 5 ×0.8 3 4.55 ~4.62 (100~85) 8 4.55 ~4.64 (100~80)5 ×0.5 3 2.72 ~4.77 (100~80)6 4.72 ~4.79 (100~75)6 ×1 4 5.43 ~5.52 (100~85)7 5.43 ~5.55 (100~80) 6 ×0.75 3 5.57 ~5.64 (100~85) 7 5.57 ~5.66 (100~80)4、公制粗牙螺紋HL-NRT (單位：mm)螺紋尺寸RH精度最小～最大(嵌合率％) M 3 ×0.5 3 3.39~3.43 (100~80)4 ×0.7 4 4.54~4.58 (100~85)5 ×0.8 4 5.61~5.66 (100~85)6 ×1 4 6.75~6.81 (100~85)8 ×1.25 5 8.93~9.01 (100~85)10 ×1.5 5 11.11~11.17 (100~90)10 ×1.25 5 10.93~11.01 (100~85)12 ×1.75 5 13.28~13.17 (100~90)12 ×1.5 5 13.11~13.17 (100~90)12 ×1.25 5 12.93~13.01 (100~85)三、螺紋下孔徑表(護套螺紋用)1、公制粗牙螺紋(單位：mm)螺紋尺寸下孔徑鑽頭直徑最小直徑最大直徑M 2.5 ×0.45 2.60 2.65 2.62.6 ×0.45 2.70 2.75 2.73 ×0.5 3.12 3.20 3.14 ×0.7 4.17 4.30 4.25 ×0.8 5.16 5.33 5.26 × 1 6.25 6.42 6.38 × 1.25 8.31 8.52 8.414 × 2 14.49 14.83 14.516 × 2 16.49 16.83 16.518 × 2.5 18.58 19.04 19.020 × 2.5 20.58 21.04 21.022 × 2.5 22.58 23.04 23.024 × 2.5 24.70 25.25 25.02、公制細牙螺紋(單位：mm) 螺紋尺寸下孔徑鑽頭直徑最小直徑最大直徑M 10 × 1 10.25 10.42 10.310 × 1.25 10.31 10.52 10.412 × 1.25 12.31 12.52 12.512 × 1.5 12.37 12.62 12.514 × 1.5 14.37 14.62 14.516 × 1.5 16.37 16.62 16.518 × 1.5 18.37 18.62 18.520 × 1.5 20.37 20.62 20.520 × 2 20.47 20.83 20.522 × 1.5 22.37 22.62 22.524 × 1.5 24.37 24.62 24.524 × 2 24.47 24.83 24.530 × 1.5 30.37 30.62 30.53、美制粗牙螺紋(單位：mm)螺紋尺寸下孔徑鑽頭直徑最小直徑最大直徑NO. 2 –56UNC 2.29 2.39 2.33 –48 2.64 2.74 2.74 –40 2.95 3.07 3.05 –40 3.25 3.38 3.36 –32 3.66 3.81 3.78 –32 4.32 4.47 4.410 –24 5.05 5.21 5.112 –24 5.61 5.77 5.71/4 –20 6.63 6.78 6.75/16 –8 8.33 8.48 8.43/8 –16 9.91 10.11 10.07/16 –14 11.51 11.76 11.51/2 –13 13.08 13.34 13.19/16 –12 14.68 14.94 14.74、美制細牙螺紋(單位：mm)螺紋尺寸下孔徑鑽頭直徑最小直徑最大直徑NO. 4 –48UNF 2.97 3.05 3.010 –32 4.98 5.13 5.01/4 –28 6.53 6.71 6.65/16 –24 8.20 8.38 8.23/8 –24 9.78 9.96 9.87/16 –20 11.43 11.63 11.51/2 –20 13.03 13.26 13.19/16 –18 14.66 14.88 14.75/8 –18 16.26 16.48 16.33/4 –16 19.43 19.68 19.57/8 –14 22.61 22.86 22.71 –12 25.76 26.04 26.0各種換算表管用螺絲基準寸法(mm)規格英制JIS(PT) 美式ASA(NPT)山數外徑有效徑山數外徑有效徑1/16 7.723 27 7.77 7.142 1/8 28 9.728 9.147 27 10.116 9.489 1/4 19 13.157 12.301 18 13.427 12.487 3/8 19 16.662 15.806 18 16.866 15.926 1/2 14 20.955 19.793 14 20.980 19.772 3/4 14 26.441 25.279 14 26.326 25.1171 11 33.249 31.770 111/2 33.932 31.46111/4 11 41.910 40.431 111/2 41.689 40.218 11/2 11 47.803 46.324 111/2 47.689 46.2872 11 59.614 58.135 111/2 59.796 58.32521/2 11 75.184 73.705 8 72.273 70.1593 11 87.884 86.405 8 88.182 86.06831/2 11 100.330 98.851 8 100.691 98.7764 11 113.030 111.551 8 113.548 111.43341/2 11 125.730 124.2515 11 138.430 136.951 8 141.3 138.41251/2 11 151.130 149.6516 11 163.830 162.351 8 168.3 165.2527 11 189.230 187.7518 11 214.630 213.151 8 219.1 215.901美制螺絲外徑公厘(mm)換算表規格吋mmNO. 0 0.0600 1.5241 0.0730 1.8542 0.0860 2.1843 0.0990 2.5154 0.1120 2.8455 0.1250 3.1756 0.1380 3.5058 0.1640 4.16610 0.1900 4.82612 0.2160 5.486山數節距換算表山數(每25.4mm) 節距mm 100 0.254080 0.317572 0.352864 0.396960 0.423356 0.453648 0.529244 0.577340 0.635036 0.705632 0.793828 0.907124 1.058320 1.270018 1.411116 1.587514 1.814313 1.953812 2.116711 2.309110 2.54009 2.82228 3.17507 3.62866 4.23335 5.08004 1/2 5.64444 6.35003 1/2 7.25713 1/4 7.81543 8.46672 7/8 8.83482 3/4 9.23642 5/8 9.67622 1/2 10.1600。

攻牙底孔的使用参数表
一、螺紋下孔徑表
1、公制粗牙螺紋JIS B 0209-1982(單位：mm)
註(1)M1.4以下等級：5H、M1.6以上等級：6H (2)基於JIS B 0209-1982標準2、公制細牙螺紋-01JIS B 0211-1982(單位：mm)
(2)基於JIS B 0211-1982標準
3、美制粗牙螺紋(單位：mm)
4、美制細牙螺紋(單位：mm)
5、英制粗牙螺紋(單位：mm)
6、英制管用螺紋(單位：mm)
7、美制管用耐密斜行螺紋(NPTF‧NPSF) (單位：mm)
8、公制螺紋(NRT) (單位：mm)
二、螺紋下孔徑表(無屑絲攻用)
1、美制細牙螺紋(NRT) (單位：mm)
2、英制管用平行螺紋(NRT) (單位：mm)
3、公制螺紋(HRT) (單位：mm)
4、公制粗牙螺紋HL-NRT (單位：mm)
三、螺紋下孔徑表(護套螺紋用)
1、公制粗牙螺紋(單位：mm)
2、公制細牙螺紋(單位：mm)
3、美制粗牙螺紋(單位：mm)
各種換算表
美制螺絲外徑公厘(mm)換算表。