Description of productsTechnical Information 16. Bored hole size before tapping ( for thread forming ) ■ for Metric Threads Unit : mm Expected minor Expected minor Size Class Bored Hole Size Diameter of Internal Size Class Bored Hole Size Diameter of Internal Thread Size Thread Size M1 × 0.25 G4 0.91 0.76G50.92 G5 3.79M4 × 0.5G63.80 3.55 M1.2 × 0.25 G4 1.11 0.96 G7 3.82 G5 1.12 G5 4.63 M1.4 × 0.3 G4 1.28 1.12 M5 × 0.8 G6 4.65 4.26 G5 1.30 G7 4.66 M1.4 × 0.2 G3 1.32 1.21 G8 4.67 G4 1.46M1.6 × 0.35G51.47 1.28 M5 × 0.5 G6 4.80 4.55G74.81 G6 1.48 G5 5.53 M1.6 × 0.2 G3 1.52 1.41 M6 × 1 G6 5.55 5.06 G4 1.56 G7 5.56 ※ M1.7 × 0.35 G5 1.57 1.38 G8 5.57 G6 1.58 M6 × 0.75 G6 5.67 5.31 M1.8 × 0.35 G4 1.66G51.67 G7 5.681.48※ M6 × 0.5G65.795.55 G4 1.82M2 × 0.4G51.83 1.64 M7 × 1 G6 6.54 6.06G76.56 G6 1.85 M7 × 0.75 G7 6.68 6.31 M2 × 0.25 G4 1.90 1.76 M8 × 1.25 G7 7.44 6.81 G5 1.92 G8 7.45 M2.2 × 0.45 G5 2.01 1.79 M8 × 1 G7 7.55 7.06 G4 2.12 M8 × 0.75 G7 7.68 7.31 ※ M2.3 × 0.4 G5 2.13 1.94 M10 × 1.5 G7 9.31 8.56 G6 2.15 G8 9.33 M2.5 × 0.45 G5 2.31 2.09 M10 × 1.25 G7 9.44 8.81 G6 2.33 G8 9.45 M2.5 × 0.35 G4 2.35 2.18 M10 × 1 G7 9.55 9.06 G5 2.37 M12 × 1.75 G8 11.20 10.32 ※ M2.6 × 0.45 G5 2.41 2.19 G9 11.21 G6 2.43 M12 × 1.5 G8 11.31 10.56 ※ M2.6 × 0.35 G5 2.47 2.28 G9 11.32 G6 2.48 M12 × 1.25 G8 11.43 10.81 G5 2.79 G9 11.45 M3 × 0.5 G6 2.81 2.55 M12 × 1 G7 11.55 11.06 G7 2.82 M14 × 2 G9 13.08 12.07 G8 2.83 G10 13.10 M3 × 0.35 G5 2.85G62.87 2.68 M14 × 1.5 G9 13.32 12.56M14 × 1G813.5513.06 G5 3.24M3.5 × 0.6G63.25 2.95 M16 × 2 G9 15.08 14.07G1015.09 G7 3.26 M16 × 1.5 G9 15.31 14.56 M3.5 × 0.35 G5 3.35 3.18 M16 × 1 G8 15.55 15.06 G6 3.36 M18 × 1.5 G9 17.31 16.56 G5 3.69 G10 17.32 M4 × 0.7 G6 3.70 3.35 M20 × 2.5 G11 18.86 17.58 G7 3.72 M20 × 1.5 G9 19.31 18.56 G8 3.73 G10 19.32 Sizes with * mark are deleted from JIS. Technical-48