Threaded Insert Nominal Length (UNC)

Nominal
Diameter		 Pitch
(mm)		 Drill Bit
Diameter (mm)		 Drilling Diameter Tap Nominal Length
min. max. Min Outer
Diameter		 1d 1.5d 2d 2.5d 3d
2-56 0.453 2.4 2.30 2.50 2.77 2.18 3.28 4.37 5.46 6.55
3-48 0.529 2.7 2.65 2.80 3.20 2.51 3.76 5.03 6.30 7.54
4-40 0.635 3.1 3.00 3.15 3.67 2.84 4.27 5.69 7.11 8.53
5-40 0.635 3.4 3.33 3.50 4.00 3.17 4.75 6.35 7.92 9.52
6-32 0.794 3.8 3.68 3.89 4.54 3.50 5.26 7.01 8.76 10.51
8-32 0.794 4.4 4.34 4.52 5.20 4.16 6.25 8.33 10.41 12.50
10-24 1.058 5.2 5.06 5.28 6.20 4.82 7.24 9.65 12.06 14.48
12-24 1.058 5.8 5.72 5.92 6.86 5.48 8.23 10.97 13.71 16.46
1/4-20 1.270 6.7 6.62 6.86 8.00 6.35 9.52 12.70 15.87 19.05
5/16-18 1.411 8.4 8.24 8.49 9.77 7.92 11.91 15.87 19.83 23.80
3/8-16 1.588 10.0 9.89 10.12 11.59 9.52 14.27 19.05 23.80 28.57
7/16-14 1.814 11.6 11.51 11.78 13.47 11.11 16.66 22.22 27.78 33.32
1/2-13 1.954 13.2 13.12 13.40 15.24 12.70 19.05 25.40 31.75 38.10
9/16-12 2.117 14.9 14.75 15.03 17.04 14.27 21.43 28.57 35.71 42.85
5/8-11 2.309 16.5 16.38 16.68 18.88 15.87 23.80 31.75 39.67 47.62
3/4-10 2.540 19.8 19.60 19.91 22.35 19.05 28.57 38.10 47.62 57.15
7/8-9 2.822 23.0 22.84 23.18 25.89 22.22 33.32 44.45 55.55 66.67
1″-8 3.175 26.4 26.09 26.47 29.53 25.40 38.10 50.80 63.50 76.20
1″ 1/8-7 3.629 29.5 29.36 29.74 33.29 28.57 42.85 57.15 71.42 85.72
1″ 1/4-7 3.629 32.8 32.54 32.92 36.46 31.75 47.62 63.50 79.37 95.25
1″ 3/8-6 4.234 36.2 35.84 36.35 40.42 34.92 52.37 69.85 87.30 104.77
1″ 1/2-6 4.234 39.5 39.02 39.53 43.62 38.10 57.15 76.20 95.25 114.30

All information is strictly informative