螺紋下孔徑表 公制粗牙螺紋 JIS B 0209-1982(單位：m m ) 螺紋尺寸 鑽頭直徑 崁合度區分：中(注 1)2 級(注 2) 下孔徑 崁合度區分：中(註 1)2 級(註 2) 內螺紋小徑 最小直徑 最大直徑 M 1 × 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 × 1 5 5.13 (80%) 4.917 5.153 7 × 1 6 6.13 (80%) 5.917 6.153 8 × 1.25 6.8 6.85 (85%) 6.647 6.912 9 × 1.25 7.8 7.85 (85%) 7.647 7.912 10 × 1.5 8.5 8.62 (85%) 8.376 8.676 11 × 1.5 9.5 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 螺紋下孔徑表 公制細牙螺紋 JIS B 0211-1982(單位：m m ) 螺紋尺寸 鑽頭直徑 崁合度區分：中(注 1)2 級(注 2) 下孔徑...
