HeliCoil Size Chart
HELICOIL® Plus installation
Drilling
Tapping
Form Tapping
Insertion of Thred Insert
Installation
Breaking off the tang
Metric – HeliCoil Insert Drill Sizes
Metric | ||||||
Insert Size | Drill Size | Screw Thread Insert Length | ||||
1D | 1.5D | 2D | 2.5D | 3D | ||
M2 x 0.4 | 2.10 | 2.00 | 3.00 | 4.00 | 5.00 | 6.00 |
M2.2 x 0.45 | 2.30 | 2.20 | 3.30 | 4.40 | 5.50 | 6.60 |
M2.5 x 0.45 | 2.60 | 2.50 | 3.75 | 5.00 | 6.25 | 7.50 |
M3 x 0.5 | 3.10 | 3.00 | 4.50 | 6.00 | 7.50 | 9.00 |
M3.5 x 0.6 | 3.60 | 3.50 | 5.25 | 7.00 | 8.75 | 10.50 |
M4 x 0.7 | 4.10 | 4.00 | 6.00 | 8.00 | 10.00 | 12.00 |
M4.5 x 0.75 | 4.70 | 4.50 | 6.75 | 9.00 | 11.25 | 13.50 |
M5 x 0.8 | 5.20 | 5.00 | 7.50 | 10.00 | 12.50 | 15.00 |
M6 x 1.0 | 6.20 | 6.00 | 9.00 | 12.00 | 15.00 | 18.00 |
M7 x 1.0 | 7.20 | 7.00 | 10.50 | 14.00 | 17.50 | 21.00 |
M8 x 1.0 | 8.20 | 8.00 | 12.00 | 16.00 | 20.00 | 24.00 |
M8 x 1.25 | 8.30 | 8.00 | 12.00 | 16.00 | 20.00 | 24.00 |
M9 x 1.25 | 9.30 | 9.00 | 13.50 | 18.00 | 22.50 | 27.00 |
M10 x 1.0 | 10.30 | 10.00 | 15.00 | 20.00 | 25.00 | 30.00 |
M10 x 1.25 | 10.30 | 10.00 | 15.00 | 20.00 | 25.00 | 30.00 |
M10 x 1.5 | 10.30 | 10.00 | 15.00 | 20.00 | 25.00 | 30.00 |
M11 x 1.5 | 11.30 | 11.00 | 16.50 | 22.00 | 27.50 | 33.00 |
M12 x 1.25 | 12.30 | 12.00 | 18.00 | 24.00 | 30.00 | 36.00 |
M12 x 1.5 | 12.40 | 12.00 | 18.00 | 24.00 | 30.00 | 36.00 |
M12 x 1.75 | 12.40 | 12.00 | 18.00 | 24.00 | 30.00 | 36.00 |
M14 x 1.25 | 14.30 | 14.00 | 21.00 | 28.00 | 35.00 | 42.00 |
M14 x 1.5 | 14.30 | 14.00 | 21.00 | 28.00 | 35.00 | 42.00 |
M14 x 2.0 | 14.30 | 14.00 | 21.00 | 28.00 | 35.00 | 42.00 |
M16 x 1.5 | 16.25 | 16.00 | 24.00 | 32.00 | 40.00 | 48.00 |
M16 x 2.0 | 16.50 | 16.00 | 24.00 | 32.00 | 40.00 | 48.00 |
M18 x 1.5 | 18.25 | 18.00 | 27.00 | 36.00 | 45.00 | 54.00 |
M18 x 2.0 | 18.50 | 18.00 | 27.00 | 36.00 | 45.00 | 54.00 |
M18 x 2.5 | 18.50 | 18.00 | 27.00 | 36.00 | 45.00 | 54.00 |
M20 x 1.5 | 20.25 | 20.00 | 30.00 | 40.00 | 50.00 | 60.00 |
M20 x 2.0 | 20.50 | 20.00 | 30.00 | 40.00 | 50.00 | 60.00 |
M20 x 2.5 | 20.50 | 20.00 | 30.00 | 40.00 | 50.00 | 60.00 |
M22 x 1.5 | 22.50 | 22.00 | 33.00 | 44.00 | 55.00 | 66.00 |
M22 x 2.0 | 22.50 | 22.00 | 33.00 | 44.00 | 55.00 | 66.00 |
M22 x 2.5 | 22.50 | 22.00 | 33.00 | 44.00 | 55.00 | 66.00 |
M24 x 1.5 | 24.25 | 24.00 | 36.00 | 48.00 | 60.00 | 72.00 |
M24 x 2.0 | 24.25 | 24.00 | 36.00 | 48.00 | 60.00 | 72.00 |
M24 x 3.0 | 24.75 | 24.00 | 36.00 | 48.00 | 60.00 | 72.00 |
M27 x 2 | 27.50 | 27.00 | 40.50 | 54.00 | 67.50 | 81.00 |
M27 x 3.0 | 27.50 | 27.00 | 40.50 | 54.00 | 67.50 | 81.00 |
M30 x 1.5 | 30.50 | 30.00 | 45.00 | 60.00 | 75.00 | 90.00 |
M30 x 2.0 | 30.50 | 30.00 | 45.00 | 60.00 | 75.00 | 90.00 |
M30 x 3.5 | 30.50 | 30.00 | 45.00 | 60.00 | 75.00 | 90.00 |
M33 x 2.0 | 33.50 | 33.00 | 49.50 | 66.00 | 82.50 | 99.00 |
M36 x 2.0 | 36.50 | 36.00 | 54.00 | 72.00 | 90.00 | 108.00 |
M36 x 4.0 | 36.50 | 36.00 | 54.00 | 72.00 | 90.00 | 108.00 |
M39 x 2.0 | 39.50 | 39.00 | 58.50 | 78.00 | 97.50 | 117.00 |
M39 x 4.0 | 39.50 | 39.00 | 58.50 | 78.00 | 97.50 | 117.00 |
UNC / UNF – HeliCoil Insert Drill Sizes
UNC | ||||||
Insert Size | Drill Size | Wire Thread Insert Length | ||||
1D | 1.5D | 2D | 2.5D | 3D | ||
2-56 | 2.3 mm | 0.086 | 0.129 | 0.172 | 0.215 | 0.258 |
3-48 | 2.7 mm | 0.099 | 0.148 | 0.198 | 0.248 | 0.297 |
4-40 | 3.0 mm | 0.112 | 0.168 | 0.224 | 0.280 | 0.336 |
5-40 | 3.4 mm | 0.125 | 0.188 | 0.250 | 0.312 | 0.375 |
6-32 | 3.7 mm | 0.138 | 0.207 | 0.276 | 0.345 | 0.414 |
8-32 | 11/64 | 0.164 | 0.246 | 0.328 | 0.410 | 0.492 |
10-24 | 5.1 mm | 0.190 | 0.285 | 0.380 | 0.475 | 0.570 |
12-24 | 5.8 mm | 0.216 | 0.324 | 0.432 | 0.540 | 0.648 |
1/4-20 | 6.7 mm | 0.250 | 0.375 | 0.500 | 0.625 | 0.750 |
5/16-18 | 8.3 mm | 0.312 | 0.469 | 0.625 | 0.781 | 0.938 |
3/8-16 | 9.9 mm | 0.375 | 0.562 | 0.750 | 0.938 | 1.125 |
7/16-14 | 29/64 | 0.438 | 0.656 | 0.875 | 1.094 | 1.313 |
1/2-13 | 33/64 | 0.500 | 0.750 | 1.000 | 1.250 | 1.500 |
9/16-12 | 14.75 mm | 0.562 | 0.844 | 1.125 | 1.406 | 1.688 |
5/8-11 | 16.5 mm | 0.625 | 0.938 | 1.250 | 1.563 | 1.875 |
3/4-10 | 19.75 mm | 0.750 | 1.125 | 1.500 | 1.875 | 2.250 |
7/8-9 | 23.0 mm | 0.875 | 1.313 | 1.750 | 2.188 | 2.625 |
1-8 | 1-1/32 | 1.000 | 1.500 | 2.000 | 2.500 | 3.000 |
1.1/8-7 | 1-5/32 | 1.125 | 1.688 | 2.250 | 2.813 | 3.375 |
1.1/4-7 | 1-9/32 | 1.250 | 1.875 | 2.500 | 3.125 | 3.750 |
1.3/8-6 | 36.0 | 1.375 | 2.063 | 2.750 | 3.438 | 4.125 |
1.1/2-6 | 1-35/64 | 1.500 | 2.250 | 3.000 | 3.750 | 4.500 |
UNF | ||||||
Insert Size | Drill Size | Wire Thread Insert Length | ||||
1D | 1.5D | 2D | 2.5D | 3D | ||
2-64 | 2.3 mm | 0.086 | 0.129 | 0.172 | 0.215 | 0.258 |
3-56 | 2.65 mm | 0.099 | 0.148 | 0.198 | 0.248 | 0.297 |
4-48 | 3.0 mm | 0.112 | 0.168 | 0.224 | 0.280 | 0.336 |
5-44 | 3.3 mm | 0.125 | 0.188 | 0.250 | 0.312 | 0.375 |
6-40 | 3.7 mm | 0.138 | 0.207 | 0.276 | 0.345 | 0.414 |
8-36 | 11/64 | 0.164 | 0.246 | 0.328 | 0.410 | 0.492 |
10-32 | 5.1 mm | 0.190 | 0.285 | 0.380 | 0.475 | 0.570 |
1/4-28 | 6.6 mm | 0.250 | 0.375 | 0.500 | 0.625 | 0.750 |
5/16-24 | 8.2 mm | 0.312 | 0.469 | 0.625 | 0.781 | 0.938 |
3/8-24 | 9.8 mm | 0.375 | 0.562 | 0.750 |
BSW / BSF – HeliCoil Insert Drill Sizes
BSW | ||||||
Insert Size | Drill Size | Wire Thread Insert Length | ||||
1D | 1.5D | 2D | 2.5D | 3D | ||
1/8-40 | 3.3 mm | 0.125 | 0.188 | 0.250 | 0.313 | 0.375 |
3/16-24 | 5.0 mm | 0.188 | 0.281 | 0.375 | 0.469 | 0.563 |
1/4-20 | 6.7 mm | 0.250 | 0.375 | 0.500 | 0.625 | 0.750 |
5/16-18 | 21/64 | 0.313 | 0.469 | 0.625 | 0.781 | 0.938 |
3/8-16 | 25/64 | 0.375 | 0.563 | 0.750 | 0.938 | 1.125 |
7/16-14 | 29/64 | 0.438 | 0.656 | 0.875 | 1.094 | 1.313 |
1/2-12 | 33/64 | 0.500 | 0.750 | 1.000 | 1.250 | 1.500 |
9/16-12 | 37/64 | 0.562 | 0.844 | 1.125 | 1.406 | 1.688 |
5/8-11 | 21/32 | 0.625 | 0.938 | 1.250 | 1.563 | 1.875 |
11/16-11 | 23/32 | 0.688 | 1.031 | 1.375 | 1.719 | 2.063 |
3/4-10 | 25/32 | 0.750 | 1.125 | 1.500 | 1.875 | 2.250 |
7/8-9 | 29/32 | 0.875 | 1.313 | 1.750 | 2.188 | 2.625 |
1-8 | 1-1/32 | 1.000 | 1.500 | 2.000 | 2.500 | 3.000 |
1.1/8-7 | 1-11/64 | 1.125 | 1.688 | 2.250 | 2.813 | 3.375 |
1.1/4-7 | 1-19/64 | 1.250 | 1.875 | 2.500 | 3.125 | 3.750 |
1.1/2-6 | 1-35/64 | 1.500 | 2.250 | 3.000 | 3.750 | 4.500 |
BSF | ||||||
Insert Size | Drill Size | Wire Thread Insert Length | ||||
1D | 1.5D | 2D | 2.5D | 3D | ||
3/16-32 | 4.9 mm | 0.188 | 0.281 | 0.375 | 0.469 | 0.563 |
7/32-28 | 5.8 mm | 0.219 | 0.328 | 0.438 | 0.547 | 0.656 |
1/4-26 | 6.6 mm | 0.250 | 0.375 | 0.500 | 0.625 | 0.750 |
9/32-26 | 7.4 mm | 0.281 | 0.422 | 0.563 | 0.703 | 0.844 |
5/16-22 | 8.3 mm | 0.313 | 0.469 | 0.625 | 0.781 | 0.938 |
3/8-20 | 9.8 mm | 0.375 | 0.563 | 0.750 | 0.938 | 1.125 |
7/16-18 | 29/64 | 0.438 | 0.656 | 0.875 | 1.094 | 1.313 |
1/2-16 | 33/64 | 0.500 | 0.750 | 1.000 | 1.250 | 1.500 |
9/16-16 | 37/64 | 0.563 | 0.844 | 1.125 | 1.406 | 1.688 |
5/8-14 | 41/64 | 0.625 | 0.938 | 1.250 | 1.563 | 1.875 |
11/16-14 | 45/64 | 0.688 | 1.031 | 1.375 | 1.719 | 2.063 |
3/4-12 | 49/64 | 0.750 | 1.125 | 1.500 | 1.875 | 2.250 |
13/16-12 | 53/64 | 0.813 | 1.219 | 1.625 | 2.031 | 2.438 |
7/8-11 | 57/64 | 0.875 | 1.313 | 1.750 | 2.188 | 2.625 |
1-10 | 1-1/32 | 1.000 | 1.500 | 2.000 | 2.500 | |
1.1/8-9 | 1-5/32 | 1.125 | 1.688 | 2.250 |
G (BSPF) / BA – HeliCoil Insert Drill Sizes
G (BSPF) | ||||||
Insert Size | Drill Size | Screw Thread Insert Length | ||||
1D | 1.5D | 2D | 2.5D | 3D | ||
1/8-28 | 25/64 | 0.125 | 0.188 | 0.250 | 0.313 | 0.375 |
1/4-19 | 17/32 | 0.250 | 0.375 | 0.500 | 0.625 | 0.750 |
3/8-19 | 43/64 | 0.375 | 0.563 | 0.750 | 0.938 | 1.125 |
1/2-14 | 27/32 | 0.500 | 0.750 | 1.000 | 1.250 | 1.500 |
5/8-14 | 59/64 | 0.625 | 0.938 | 1.250 | 1.563 | 1.875 |
3/4-14 | 1-1/6 | 0.750 | 1.125 | 1.500 | 1.875 | |
7/8-14 | 1-13/64 | 0.875 | 1.313 | 1.750 | 2.625 | |
1-11 | 1-21/64 | 1.000 | 1.500 | 2.000 | ||
1.1/4-11 | 1-43/64 | 1.250 | 1.875 | 2.500 | 3.750 | |
1.1/2-11 | 1-29/32 | 1.500 | 2.250 | 3.000 | 4.500 | |
BA | ||||||
Insert Size | Drill Size | Screw Thread Insert Length | ||||
1D | 1.5D | 2D | 2.5D | 3D | ||
0BA | 6.2 mm | 0.236 | 0.354 | 0.472 | 0.590 | 0.708 |
1BA | 5.5 mm | 0.209 | 0.313 | 0.418 | 0.522 | 0.627 |
2BA | 4.9 mm | 0.185 | 0.277 | 0.370 | 0.462 | 0.555 |
3BA | 4.3 mm | 0.161 | 0.241 | 0.322 | 0.402 | 0.483 |
4BA | 3.8 mm | 0.142 | 0.213 | 0.284 | 0.355 | 0.426 |
5BA | 3.3 mm | 0.126 | 0.189 | 0.252 | 0.315 | 0.378 |
6BA | 2.9 mm | 0.110 | 0.165 | 0.220 | 0.275 | 0.330 |