Security Torx (Tamper-Resistant TR)
Direct Answer
Security Torx (Tamper-Resistant Torx / Pin-in-Torx / Torx TR) is a tamper-evident variant of the standard hexalobular drive. Featuring a hardened solid cylindrical metal post in the center of the 6-lobed recess, it prevents standard flat, hex, or standard Torx driver bits from inserting, requiring a specialized hollow-tipped security bit.
Source: ISO 10664 Variant / ASME B18.6.3 Security Recesses
Specs
| Drive Geometry | Standard 6-lobed Torx star with a centered solid cylindrical metal post |
| Tool Bit Requirement | Hollow-center / Bore-hole driver bit (e.g. TR20 bit has a drilled center) |
| Standard Sizing Tiers | T6H, T7H, T8H, T9H, T10H, T15H, T20H, T25H, T27H, T30H, T40H ('H' or 'TR' designation) |
| Tamper Resistance Level | Medium (Deters unauthorized consumer disassembly without specialty tools) |
| Primary Applications | Public infrastructure (restroom partitions, subway signs), video game consoles (Xbox, PlayStation controllers), consumer power tools |
Pin-in-Torx Mechanism
By leaving a solid metal pillar protruding from the center floor of the star recess, a standard solid Torx bit (such as a T8 or T10) physically collides with the pin, preventing the bit's lobes from engaging the screw walls. The mating Security Torx bit has a precision-drilled coaxial hole in its center to clear the post.
Durability and Torque Reduction
Because the security bit has a hollow bore, its outer metal walls are thinner than a solid Torx bit. Under extreme manual or impact torque, hollow security bits are more prone to fracturing at the lobe roots than solid Torx bits.