Hole Sizes for Cut Tapping Metric System （孔大小减少攻公制）.pdf

Hole Sizes for Cut Tapping Metric System Notes: 1. This chart is supplied as a recommendation only. Actual sizes may vary depending on application and the material being tapped. Other thread and hole sizes are available upon request. 2. For aluminum or other soft materials a hole minor diameter on the low side of the suggested range is recommended. For harder materials, a hole minor diameter on the high side of the suggested range is recommended. 3. These recommendations are for cutting with regular preload-locking threading taps. 4. Preload-locking threads can be applied to threading tools in sizes from 0.30 mm. Metric Hole Minor Hole Minor Drill Metric Hole Minor Hole Minor Drill Thread Dia. Min Dia. Max Size* Thread Dia. Min Dia. Max Size* Size (mm) (mm) Size (mm) (mm) M1.6 x 0.35 1.373 1.418 #54 M14.0 x 1.50 12.725 13.030 13 mm M2.0 x 0.40 1.740 1.792 #50 M14.0 x 2.00 12.319 12.700 31/64 M2.5 x 0.45 2.210 2.261 #43 M16.0 x 1.50 14.732 15.037 15 mm M3.0 x 0.50 2.667 2.743 #36 M16.0 x 2.00 14.300 14.707 9/16 M3.5 x 0.60 3.099 3.200 1/8 M18.0 x 1.50 16.739 17.018 17 mm M4.0 x 0.70 3.556 3.632 #28 M18.0 x 2.50 15.875 16.383 5/8 M4.5 x 0.75 4.013 4.115 #21 M20.0 x 1.50 18.745 19.025 19 mm M5.0 x 0.80 4.318