Torx - also called star drive - uses a six-point star-shaped pattern that eliminates cam-out and distributes torque evenly. Developed by Camcar Textron in 1967, Torx is now standard in automotive, electronics, appliances, and construction.
Torx Size Chart
| Torx Size | Point-to-Point (mm) | Typical Application |
|---|---|---|
| T1 | 0.81 | Micro electronics |
| T3 | 0.99 | Phones (older iPhones) |
| T4 | 1.28 | Hard drives, small electronics |
| T5 | 1.42 | Laptops (Ultrabook screws) |
| T6 | 1.70 | Laptops, phones, drones |
| T8 | 2.31 | Xbox controllers, Ring doorbells, security cameras |
| T10 | 2.74 | Automotive interior, appliances |
| T15 | 3.27 | Automotive, decking screws |
| T20 | 3.86 | Automotive, construction |
| T25 | 4.43 | Automotive, construction, decking - most common large Torx |
| T27 | 4.99 | Automotive, truck assembly |
| T30 | 5.52 | Heavy automotive, brake rotors |
| T40 | 6.65 | Structural automotive, equipment |
| T45 | 7.82 | Heavy equipment |
| T50 | 8.83 | Large bolts, structural work |
| T55–T100 | 9.92–16.96 | Industrial and heavy machinery |
Security Torx (Tamper-Resistant)
Security Torx screws have a small pin in the centre of the star recess. A standard Torx bit won't fit - you need a security Torx bit with a matching hole. These are used on public fixtures, game consoles (Xbox, PS4), and equipment where manufacturers want to discourage disassembly. Security sizes are written as T8H, T10H, T15H, etc.
If you work on game consoles or smart home devices, a T8 security Torx bit is used on nearly all Xbox and Ring doorbell models.
Why Torx Over Phillips?
- Zero cam-out - the star shape locks the bit in the screw
- Higher torque transfer - force spreads across 6 lobes instead of 4
- Longer bit life - less wear from slipping
- Better for power tools - the positive engagement prevents bit walking
The tradeoff: Torx requires a wider selection of sizes than Phillips (which covers most jobs with PH1–PH3). A Torx bit set with T8, T10, T15, T20, T25, and T30 covers the vast majority of tasks.
Related Guides
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