CE RD PHG 250 0603 Copyright 2003 by Wurth 05 0210 Tap and Drill ChartConversion Tables Metric and Imperial UNC Unified National Coarse Size Thread Recommended inch per inch drill size 16 4 5 3 25 6 5 0 34 8 4 7 44 0 3 3 2 54 0 3 8 63 2 3 6 83 2 2 9 10 24 25 12 24 16 14 20 1364 516 18 1764 38 16 516 716 14 38 12 13 2764 916 12 3164 58 11 3564 34 10 2132 78 9 4964 18 7 8 118 7 6364 114 7 1764 138 6 1732 112 6 11132 134 5 1916 2 4 12 12532 Metric Iso Coarse Size Thread Recommended mm pitch drill size 16 035 364 17 035 55 18 0 5 4 20 4 0 1 1 0 25 045 40 30 5 4 0 35 060 33 40 7 0 3 0 45 075 27 5 080 1164 6 10 1364 71 0 6 0 81 2 5 H 91 2 5 5 1 6 10 15 1132 11 15 38 12 175 1332 14 20 3164 16 20 916 18 25 3964 20 25 4564 22 25 2532 24 30 5364 27 30 6164 30 35 1364 33 35 11164 36 40 114 39 40 138 UNC Unified National Fine Size Thread Recommended inch per inch drill size 08 0 3 6 4 17 2 5 3 26 4 5 0 35 6 4 5 44 8 4 2 54 4 3 7 64 0 3 3 83 6 9 6 4 10 32 21 12 26 14 14 28 732 516 24 1764 38 24 Q 716 20 2564 12 20 2064 916 18 3364 58 18 3764 34 16 1116 78 14 1316 1 1 2 5964 1 14 1516 118 12 1364 114 12 11164 138 12 11964 112 12 12764 Metric Iso Fine Size Thread Recommended mm pitch drill size 40 5 0 2 0 50 5 0 1 6 60 7 5 5 70 7 5 D 81 0 0 J 10 125 1132 10 100 T 12 150 2764 12 125 2764 12 100 716 14 15 3164 16 15 3764 18 20 58 18 15 7132 20 20 4564 20 15 4764 22 20 2532 22 15 1310 24 20 78 24 15 78