Threaded Insert Drilling Depth (UNC)

Nominal
Diameter
Pitch
(mm)
Drill Bit
Diameter (mm)
Drilling Diameter Tap Drilling Depth
min. max. Min Outer
Diameter
1d 1.5d 2d 2.5d 3d
2-56 0.453 2.4 2.30 2.50 2.77 4.2 5.3 6.4 7.5 8.6
3-48 0.529 2.7 2.65 2.80 3.20 4.9 6.2 7.4 8.7 10.0
4-40 0.635 3.1 3.00 3.15 3.67 5.7 7.1 8.6 10.0 11.4
5-40 0.635 3.4 3.33 3.50 4.00 6 7.6 9.2 10.8 12.4
6-32 0.794 3.8 3.68 3.89 4.54 7.1 8.8 10.6 12.3 14.1
8-32 0.794 4.4 4.34 4.52 5.20 7.7 9.8 11.9 14.0 16.1
10-24 1.058 5.2 5.06 5.28 6.20 9.6 12.0 14.4 16.8 19.2
12-24 1.058 5.8 5.72 5.92 6.86 10.3 13.0 15.7 18.5 21.3
1/4-20 1.270 6.7 6.62 6.86 8.00 12.1 15.2 18.4 21.6 24.8
5/16-18 1.411 8.4 8.24 8.49 9.77 14.3 18.3 22.2 26.2 30.2
3/8-16 1.588 10.0 9.89 10.12 11.59 16.7 21.4 26.2 31.0 35.7
7/16-14 1.814 11.6 11.51 11.78 13.47 19.3 24.8 30.4 35.9 41.5
1/2-13 1.954 13.2 13.12 13.40 15.24 21.5 27.8 34.2 40.5 46.9
9/16-12 2.117 14.9 14.75 15.03 17.04 23.8 31.0 38.1 45.2 52.4
5/8-11 2.309 16.5 16.38 16.68 18.88 26.3 34.2 42.1 50.1 58.0
3/4-10 2.540 19.8 19.60 19.91 22.35 30.5 40.0 49.5 59.0 68.6
7/8-9 2.822 23.0 22.84 23.18 25.89 34.9 46.0 57.2 68.3 79.4
1″-8 3.175 26.4 26.09 26.47 29.53 39.7 52.4 65.1 77.8 90.5
1″ 1/8-7 3.629 29.5 29.36 29.74 33.29 44.9 59.2 73.5 87.8 102.0
1″ 1/4-7 3.629 32.8 32.54 32.92 36.46 48.1 64.0 79.8 96.0 111.8
1″ 3/8-6 4.234 36.2 35.84 36.35 40.42 54.0 71.4 88.9 106.0 124.0
1″ 1/2-6 4.234 39.5 39.02 39.53 43.62 57.2 76.2 95.3 115.0 133.0

All information is strictly informative