Hex / Allen vs. Pozidriv
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.
The Pozidriv drive (ANSI Type IA cross recess / ISO 4757) is an improved cruciform drive developed by GKN Screws and Fasteners in 1962. Identified by four secondary radial score lines etched at 45 degrees between the main cross blades, it features parallel, non-tapered sidewalls that eliminate cam-out and allow significantly higher torque transmission than Phillips.
Specification Comparison Table
10 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standard Specifications
|
ISO 4762 / DIN 912 (Socket head cap screws) / ASME B18.3 | ISO 4757 Type IA / BS 3529 / DIN 7962 |
|
Cam-Out Tendency
|
Low (Requires axial insertion depth; strips if bit is worn or undersized) | Extremely Low (Does not push driver out under high torque) |
|
Drive Geometry
|
Symmetrical 6-sided internal hexagon socket | — |
|
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 | — |
|
Visual Identification
|
— | 4 distinctive radial tick marks embossed at 45° between the main cross arms |
|
Flank Geometry
|
— | Parallel vertical sidewalls (zero taper angle, unlike Phillips 57° taper) |
|
Standard Sizing Tiers
|
— | PZ0, PZ1, PZ2 (dominant European carpentry size), PZ3, PZ4 |
|
Primary Geographical Usage
|
— | Dominant across European construction, cabinetry (IKEA furniture), and automotive |