Hex / Allen vs. Torx
Comparing 2 standards across 10 specifications. 10 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.
Torx (standardized as Hexalobular Internal under ISO 10664) is a 6-lobed star-shaped screw drive system developed by Camcar Textron in 1967. Engineered with a low 15-degree drive angle and curved lobes, it eliminates cam-out entirely, delivers exceptional torque transfer, and drastically extends tool bit lifespan across automotive, computing, and construction hardware.
Specification Comparison Table
10 Parameters| Parameter / Spec | ||
|---|---|---|
|
Drive Geometry
|
Symmetrical 6-sided internal hexagon socket | 6-pointed star with rounded circular lobes |
|
Cam-Out Tendency
|
Low (Requires axial insertion depth; strips if bit is worn or undersized) | Zero (Radial drive force completely eliminates axial climb) |
|
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" | — |
|
Primary Applications
|
Machine tools, bicycle components (4/5/6mm), 3D printers (2.5/3mm), flat-pack furniture | — |
|
International Standard
|
— | ISO 10664 (Hexalobular internal driving feature for bolts and screws) |
|
Drive Angle
|
— | 15 degrees (near-perpendicular torque vector) |
|
Common Sizing Tiers
|
— | T1–T5 (smartphones), T6–T10 (laptops/electronics), T15–T25 (wood/auto), T30–T50 (chassis/structural) |
|
External Variant
|
— | E-Torx (Inverted star socket for high-torque automotive bolts, E4 to E24) |