ISO 10664:2014
Torx.
Profiles included (use links to navigate): Torx
This is an explanation of data for "Torx".
ISO 10664 is leading, where nominal outer diameter A and inner diameter B are mentioned, just as the relationships mentioned for CAD are ra=1, rb≈0.72*ra, rc≈0.1*ra and rd≈0.175*ra.
The following data are used: ra=A/2, rb=0.72*ra, rc=0.1*ra.
This means that B and rd are overdetermined within the standard and are therefore ignored. From a mathematical point of view, this is a justified choice, as demonstrated by calculations.
The function generates a nominal shape, purely for representation in CAD in accordance with ISO 10664.
Do not use the shape for production data of bits and screws, as the standard works with "go" and "no go" gauges.
A designation like "10" in the table is often referred to as "T10" and always has n=6 lobes.
Torx / NLobe
| Size | ra | rb | rc | n |
|---|---|---|---|---|
| 1 | 0.45 | 0.324 | 0.045 | 6 |
| 2 | 0.5 | 0.36 | 0.05 | 6 |
| 3 | 0.6 | 0.432 | 0.06 | 6 |
| 4 | 0.675 | 0.486 | 0.0675 | 6 |
| 5 | 0.75 | 0.54 | 0.075 | 6 |
| 6 | 0.875 | 0.63 | 0.0875 | 6 |
| 8 | 1.2 | 0.864 | 0.12 | 6 |
| 10 | 1.4 | 1.008 | 0.14 | 6 |
| 15 | 1.675 | 1.206 | 0.1675 | 6 |
| 20 | 1.975 | 1.422 | 0.1975 | 6 |
| 25 | 2.25 | 1.62 | 0.225 | 6 |
| 30 | 2.8 | 2.016 | 0.28 | 6 |
| 40 | 3.375 | 2.43 | 0.3375 | 6 |
| 45 | 3.965 | 2.8548 | 0.3965 | 6 |
| 50 | 4.475 | 3.222 | 0.4475 | 6 |
| 55 | 5.675 | 4.086 | 0.5675 | 6 |
| 60 | 6.725 | 4.842 | 0.6725 | 6 |
| 70 | 7.85 | 5.652 | 0.785 | 6 |
| 80 | 8.875 | 6.39 | 0.8875 | 6 |
| 90 | 10.1 | 7.272 | 1.01 | 6 |
| 100 | 11.2 | 8.064 | 1.12 | 6 |