Tap Drill ChartTo give 75% Thread Depth

Tap Size BSW BSF UNC UNF BSP ANP BA ISO Metric

TPI Drill size TPI Drill size TPI Drill size TPI Drill size TPI Drill size TPI Drill size Size Drill size Tap Size mm Pitch Drill size

1/16 60 3/64 0 7 2 0:40 52 or 1.6

1/8 40 3/32 28 11/32 27 21/64 1 16 2 0:45 53 or 1.5

5/32 32 1/8 3 0:50 39 or 2.5

3/16 24 9/64 32 5/32 24 9/64 32 5/32 2 5/32 3 0:60 35 or 2.8

7/32 24 11/64 28 11/64 24 11/64 32 3/16 3 29 3.5 0:60 32 or 2.95

1/4 20 13/64 26 7/32 20 13/64 28 7/32 19 15/32 18 27/64 4 32 4 0:70 29 or 3.5

5/16 18 17/64 22 17/64 18 1/4 24 17/64 5 37 4 0:75 28 or 3.6

3/8 16 5/16 20 21/64 16 5/16 24 21/64 19 39/64 18 9/16 4.5 0:75 25 or 3.8

7/16 14 3/8 18 25/64 14 3/8 20 25/64 6 43 5 0:80 19 or 4.2

1/2 12 27/64 16 7/16 13 27/64 20 29/64 14 3/4 14 11/16 5 0:90 20 or 4.1

9/16 12 31/64 16 1/2 12 31/64 18 33/64 7 46 6 1:00 8 or 5.1

5/8 11 17/32 14 9/16 11 17/32 18 37/64 14 53/64 7 1:00 3 or 5.4

11/16 11 19/32 14 39/64 11 19/32 16 5/8 8 50 8 1:25 H or 6.8

3/4 10 21/32 12 43/64 10 21/32 16 11/16 14 31/32 14 57/64 9 1:25 N or 7.6

7/8 9 49/64 11 25/32 9 49/64 14 13/16 14 1 1/8 9 53 10 1:50 R or 8.6

1 8 7/8 10 29/32 8 7/8 12 29/32 11 1 7/32 11 1/2 1 1/8 10 54 11 1:50 3/8

1 1/8 7 63/64 9 1 1/64 7 63/64 12 1 3/64 12 1:75 13/32

1 1/4 7 1 7/64 9 1 9/64 7 1 7/64 12 1 11/64 11 1 9/16 11 1/2 1 15/32 11 3/64 14 2:00 15/32

1 3/8 6 1 7/32 8 1 1/4 6 1 13/64 12 1 19/64 16 2:00 9/16

1 1/2 6 1 11/32 8 1 3/8 6 1 11/32 12 1 27/64 11 1 51/64 11 1/2 1 23/32 12 59 18 2:50 39/64

1 5/8 5 1 7/16 8 1 1/2 20 2:50 11/16

1 3/4 5 1 9/16 7 1 39/64 5 1 9/16 11 2 1/32 22 2:50 49/64

2 4.5 1 25/32 7 1 55/64 4.5 1 25/32 11 2 17/64 11 1/2 2 3/16 24 3:00 53/64