25. Drill size and recommended hole size for forming taps Intro Metric Coarse Threads (M) Unit: mm Metric Fine Threads (MF) Unit: mm SP Size Minor DiameterClass RecommendedDrillHole SizeSizeSize Minor DiameterClass RecommendedDrillHole SizeSize Tol. Max. Min. Max. Min. Tol. Max. Min. Max. Min. ISO2X 6H (0.785) (0.729) 0.91 0.92 0.89 ISO2X 6H 5.378 5.188 5.67 5.72 5.62 M 1 × 0.25 MF 6 × 0.75 SL ISO3X 6G (0.803) (0.747) 0.92 0.93 0.91 ISO3X 6G 5.400 5.210 5.70 5.75 5.65 ISO2X 6H (0.985) (0.929) 1.11 1.12 1.09 ISO2X 6H 5.599 5.459 5.78 5.81 5.74 M 1.2 × 0.25 MF 6 × 0.5 ISO3X 6G (1.003) (0.947) 1.12 1.13 1.11 ISO3X 6G 5.619 5.479 5.80 5.83 5.76 ISO2X 6H 1.142 1.075 1.27 1.28 1.25 ISO2X 6H 7.153 6.917 7.55 7.61 7.49 M 1.4 × 0.3 MF 8 × 1 PO ISO3X 6G 1.160 1.093 1.29 1.3 1.27 ISO3X 6G 7.179 6.943 7.59 7.65 7.53 ISO2X 6H 1.321 1.221 1.46 1.48 1.43 ISO2X 6H 8.912 8.647 9.45 9.51 9.38 M 1.6 × 0.35 MF 10 × 1.25 ISO3X 6G 1.340 1.240 1.47 1.49 1.44 ISO3X 6G 8.940 8.675 9.47 9.53 9.40 ISO2X 6H 1.421 1.321 1.55 1.57 1.53 ISO2X 6H 9.153 8.917 9.55 9.61 9.49 M 1.7 × 0.35 MF 10 × 1 ISO3X 6G 1.440 1.340 1.57 1.59 1.54 ISO3X 6G 9.179 8.943 9.59 9.65 9.53 ST ISO2X 6H 1.521 1.421 1.65 1.67 1.62 ISO2X 6H 10.676 10.376 11.32 11.39 11.24 M 1.8 × 0.35 MF 12 × 1.5 ISO3X 6G 1.540 1.440 1.67 1.69 1.64 ISO3X 6G 10.708 10.408 11.35 11.42 11.27 ISO2X 6H 1.679 1.567 1.83 1.86 1.80 ISO2X 6H 10.912 10.647 11.45 11.51 11.38 M 2 × 0.4 MF 12 × 1.25 ISO3X 6G 1.698 1.586 1.85 1.87 1.82 ISO3X 6G 10.940 10.675 11.46 11.52 11.39 ROLL ISO2X 6H 1.838 1.713 2.01 2.04 1.97 ISO2X 6H 11.153 10.917 11.56 11.62 11.50 M 2.2 × 0.45 MF 12 × 1 ISO3X 6G 1.858 1.733 2.03 2.06 1.99 ISO3X 6G 11.179 10.943 11.57 11.63 11.51 ISO2X 6H 1.979 1.867 2.13 2.16 2.10 ISO2X 6H 12.676 12.376 13.32 13.39 13.24 M 2.3 × 0.4 MF 14 × 1.5 ISO3X 6G 1.998 1.886 2.15 2.17 2.12 ISO3X 6G 12.708 12.408 13.35 13.42 13.27 CARBIDE ISO2X 6H 2.138 2.013 2.31 2.34 2.27 ISO2X 6H 13.153 12.917 13.55 13.61 13.49 M 2.5 × 0.45 MF 14 × 1 ISO3X 6G 2.158 2.033 2.34 2.37 2.31 ISO3X 6G 13.179 12.943 13.57 13.62 13.51 ISO2X 6H 2.238 2.113 2.41 2.44 2.37 ISO2X 6H 14.676 14.376 15.31 15.38 15.23 M 2.6 × 0.45 MF 16 × 1.5 ISO3X 6G 2.258 2.133 2.44 2.47 2.41 ISO3X 6G 14.708 14.408 15.34 15.41 15.26 LONG M ISO2X 6H 2.599 2.459 2.80 2.83 2.763×0.5 ISO2X 6H 15.153 14.917 15.55 15.61 15.49MF16×1 ISO3X 6G 2.619 2.479 2.82 2.85 2.78 ISO3X 6G 15.179 14.943 15.56 15.62 15.50 ISO2X 6H 3.010 2.850 3.25 3.29 3.21 ISO2X 6H 16.676 16.376 17.31 17.38 17.23 M 3.5 × 0.6 MF 18 × 1.5 ISO3X 6G 3.031 2.871 3.27 3.31 3.23 ISO3X 6G 16.708 16.408 17.34 17.41 17.26 HAND ISO2X 6H 3.422 3.242 3.71 3.75 3.66 ISO2X 6H 18.676 18.376 19.30 19.37 19.22 TAPS M 4 × 0.7 MF 20 × 1.5ISO3X6G3.4443.2643.733.773.68ISO3X6G18.70818.40819.3419.4119.26 ISO2X 6H 4.334 4.134 4.65 4.70 4.60 M 5 × 0.8 ISO3X 6G 4.358 4.158 4.67 4.72 4.62 ISO2X 6H 5.153 4.917 5.56 5.61 5.50 EG (STI) M 6 × 1 ISO3X 6G 5.179 4.943 5.60 5.65 5.54 ISO2X 6H 6.912 6.647 7.45 7.52 7.38 M 8 × 1.25 ISO3X 6G 6.940 6.675 7.47 7.53 7.40 SPECIALTHREADS,M ISO2X 6H 8.676 8.376 9.34 9.41 9.2610×1.5ISO3X6G8.7088.4089.379.449.29Miniature threads (S) Unit: mmRecommended GAUGES Hole SizeISO2X6H10.44110.10611.2211.311.13Size M 12 × 1.75 ISO3X 6G 10.475 10.140 11.25 11.33 11.16 Max. Min. ISO2X 6H 12.210 11.835 13.10 13.19 13.00 S 0.6 X 0.15 0.55 0.54 THREAD M 14 × 2 ISO3X 6G 12.248 11.873 13.14 13.23 13.04 S 0.7 X 0.175 0.64 0.62 MILLS ISO2X 6H 14.210 13.835 15.10 15.19 15.00 S 0.8 X 0.2 0.73 0.71 M 16 × 2 ISO3X 6G 14.248 13.873 15.14 15.23 15.04 S 0.9 X 0.225 0.82 0.80 DIES CENTER DRILLS Technical info 728