各种螺纹加工前的底孔尺寸

各种螺纹加工前的底孔尺寸 普通螺纹钻底孔的钻头尺寸表 钻底孔钻头直径的计算公式: p<1时 dT=d-p p>1时 dT?d-(1.04-1.08)p 式中: p-螺距(mm) 【说明】普通螺纹代号为“M”,牙型角a为60?, 一般连接 螺纹公称直径(mm) 多用粗牙.细牙用于薄壁零件,细牙的自锁性能较好, d- dT-攻螺纹前钻头直径(mm) 螺纹强度削弱少,但易滑扣. (mm) 推荐钻螺纹内径 螺纹内径 螺纹螺距 螺 纹螺距 推荐钻头头直径直径d p T 直径d p 直径ddT Max Min Max Min M2 粗 0.4 1.677 1.567 1.6 M27 粗 3 24.132 23.752 23.9 细 0.25 1.809 1.729 1.75 细 2 25.135 24.835 24.9 M3 粗 0.5 2.599 2.459 2.5 1.5 25.626 25.376 25.5 细 0.35 2.721 2.621 2.65 1 26.118 25.918 26.0 M4 粗 0.7 3.422 3.242 3.3 M30 粗 3.5 26.631 26.211 26.3 细 0.5 3.599 3.459 3.5 细 3 26.9 26.88 26.7 M5 粗 0.8 4.334 4.134 4.2 2 28.135 27.835 27.9 细 0.5 4.599 4.459 4.5 1.5 28.626 28.376 28.5 M6 粗 1 5.118 4.918 5.0 1 29.118 28.918 29.0 细 0.75 5.378 5.118 5.2 M33 粗 3.5 29.631 29.211 29.3 M8 粗 1.25 6.887 6.647 6.7 细 2 31.135 30.835 30.9 细 1 7.118 6.918 7.0 1.5 31.626 31.376 31.8 0.75 7.378 7.118 7.2 M36 粗 4 32.15 31.67 31.8 M10 粗 1.5 8.626 8.376 8.5 细 3 33.132 32.752 32.9 细 1.25 8.867 8.647 8.7 2 34.135 33.835 33.9 1 9.118 8.918 9.0 1.5 34.626 34.376 34.5 0.75 9.378 9.118 9.2 M39 粗 4 35.15 34.67 34.8 M12 粗 1.75 10.386 10.106 10.2 细 3 36.132 35.752 35.9 细 1.5 10.626 10.376 10.5 2 37.135 36.835 36.9 1.25 10.867 10.647 10.7 1.5 37.626 37.376 37.5 1 11.118 10.918 11.0 M42 粗 4.5 37.679 37.129 37.3 M16 粗 2 14.135 13.835 13.9 细 3 39.132 38.752 38.9 细 1.5 14.626 14.376 14.5 2 40.135 39.835 39.9 1 15.118 14.918 15.0 1.5 40.626 40.376 40.5 M20 粗 2.5 17.634 17.294 17.4 M45 粗 4.5 40.679 40.129 40.3 细 2 18.135 17.835 17.9 细 3 42.132 41.132 41.9 1.5 18.626 18.376 18.5 2 43.135 42.835 42.9 1 19.118 18.918 19.0 1.5 43.626 43.376 43.5 M24 粗 3 21.132 20.752 20.9 M48 粗 5 43.118 42.588 42.7 细 2 22.135 21.835 21.9 细 3 45.132 44.752 44.8 1.5 22.626 22.376 22.5 2 46.135 45.835 45.9 1 23.118 22.918 23.0 1.5 46.626 46.376 46.5 英寸制螺纹钻底孔的钻头尺寸表 钻底孔钻头直径的计算公式: 螺纹公称直径 铸铁与青铜 钢与黄铜 3/16”~5/8” dT=25(d-1/n) dT=25(d-1/n)+0.1 13/4”~1/” dT=25(d-1/n) dT=25(d-1/n)+0.2 2 注: dT-攻螺纹前钻头直径(mm) d-螺纹公称直径(寸) 【说明】英寸制螺纹牙型角a为55? n-每寸牙数 钻头直径dT 螺纹直径(mm) 公称 每寸 螺距 (mm) 直径d 牙数 P 铸铁 钢 大径 中径 小径 (寸) n (mm) 青铜 黄铜 dd d2 d1 3/16 24 3.7 3.7 1.058 4.762 4.085 3.408 1/4 20 5.0 5.1 1.270 6.350 5.537 4.724 5/16 18 6.4 6.5 1.411 7.938 7.034 6.131 3/8 16 7.8 7.9 1.588 9.525 8.509 7.492 7/16 14 9.1 9.3 1.814 11.112 9.951 8.789 1/2 12 10.4 10.5 2.117 12.700 11.345 9.989 5/8 11 13.3 13.5 2.309 15.875 14.397 12.918 3/4 10 16.3 16.4 2.540 19.050 17.424 15.798 7/8 9 19.1 19.3 2.822 22.225 20.418 18.611 1 8 21.9 22.0 3.175 25.400 23.367 21.334 11/ 7 24.6 24.7 3.629 28.575 26.252 23.929 8 11/ 7 27.8 27.9 3.629 31.750 29.427 27.104 4 11/ 6 33.4 33.5 4.233 38.100 35.390 32.679 2 51/ 5 35.7 35.8 5.080 41.275 38.022 34.770 8 31/ 5 38.9 39.0 5.080 44.450 41.198 37.945 4 711/ 4/ 41.4 41.5 5.644 47.625 44.011 40.397 82 12 4/ 44.6 44.7 5.644 50.800 47.186 43.572 2 12/ 4 50.0 50.2 6.350 57.150 53.084 49.019 4 12/ 4 56.3 56.5 6.350 63.500 59.434 55.369 2 312/ 3/ 61.6 61.8 7.257 69.850 65.204 60.557 42 13 3/ 67.9 68.1 7.257 76.200 71.554 66.907 2 113/ 3/ 73.6 73.8 7.815 82.550 77.546 72.542 44 113/ 3/ 79.8 80.0 7.815 88.900 83.896 78.892 24 33/ 3 85.4 85.6 8.467 95.250 89.829 84.409 4 4 3 91.7 91.9 8.467 101.600 96.179 90.759 圆柱管螺纹钻底孔的钻头尺寸表 【说明】非螺纹密封的圆柱管螺纹,代号为“G”,牙型角a为55?.多用于压力为21.568Mpa(16kgf/cm)以下的水,煤气管路,润滑和电线管路系统. 螺纹直径(mm) 公称 每寸 钻头 螺距 直径d 牙数 直 径dT P 大径 中径 小径 (寸) n (mm) (mm) dd d2 d1 G 1/8 28 8.80 0.907 9.728 9.147 8.566 G 1/4 19 11.70 13.157 12.301 11.445 1.337 G 3/8 19 15.20 16.662 15.806 14.950 G 1/2 14 18.90 20.955 19.793 18.631 G 5/8 14 20.80 22.911 21.749 20.587 1.814 G 3/4 14 24.30 26.441 25.279 24.117 G 7/8 14 28.10 30.201 29.039 27.877 G 1 11 30.50 33.249 31.770 30.291 1G 1/ 11 35.20 37.897 36.418 34.939 8 1G 1/ 11 39.20 41.910 40.431 38.952 4 3G 1/ 11 41.60 44.325 42.846 41.367 8 1G 1/ 11 45.10 47.803 46.324 44.845 2 3G 1/ 11 51.00 53.746 52.267 50.788 4 G 2 11 57.00 59.614 58.135 56.656 1G 2/ 11 63.00 2.309 65.710 64.231 62.752 4 1G 2/ 11 72.50 75.184 73.705 72.226 2 3G 2/ 11 78.50 81.534 80.055 78.576 4 G 3 11 85.20 87.884 86.405 84.926 1G 3/ 11 97.60 100.330 98.851 97.372 2 G 4 11 110.20 113.030 111.551 110.072 G 5 11 135.70 138.430 136.951 135.472 G 6 11 161.10 163.830 162.351 160.872