Hex / Allen vs. Security Torx
Comparing 2 standards across 9 specifications. 9 key differences identified.
The Hex drive (Allen socket / Internal Hexagon, standardized under ISO 4026 and DIN 912) is a 6-sided symmetrical polygonal drive recess developed in the early 1900s by William G. Allen. Widely used in socket head cap screws, bicycle components, and flat-pack furniture, it provides high clamping torque with compact cylindrical head profiles.
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.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Drive Geometry
|
Symmetrical 6-sided internal hexagon socket | Standard 6-lobed Torx star with a centered solid cylindrical metal post |
|
Primary Applications
|
Machine tools, bicycle components (4/5/6mm), 3D printers (2.5/3mm), flat-pack furniture | Public infrastructure (restroom partitions, subway signs), video game consoles (Xbox, PlayStation controllers), consumer power tools |
|
Standard Specifications
|
ISO 4762 / DIN 912 (Socket head cap screws) / ASME B18.3 | — |
|
Metric Standard Sizes
|
1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 8.0, 10.0, 12.0, 14.0, 17.0 mm | — |
|
Imperial Standard Sizes
|
0.050", 1/16", 5/64", 3/32", 1/8", 5/32", 3/16", 1/4", 5/16", 3/8" | — |
|
Cam-Out Tendency
|
Low (Requires axial insertion depth; strips if bit is worn or undersized) | — |
|
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) |