Screwdriver Drive Types Explained: Phillips, Pozidriv, Torx, Slotted and Hex

Ask a hardware buyer to open a screwdriver set and they will find at least half a dozen drive types. Phillips, Pozidriv, Torx, slotted, hex and square drives each follow their own standard, suit different fasteners and fail in different ways. For importers, understanding drives matters twice over: it decides which tools your market actually needs, and it tells you how to read a specification. This guide walks through the drives you will meet most often.

Why the drive type matters

A drive is the interface between your tool and the screw. A good drive transfers torque cleanly; a poor one slips, rounds the screw head or breaks the tip. Three things decide this: how many contact points the drive has, how deeply the tool engages, and whether the design is prone to cam-out — the tendency to slip out of the screw under load.

Slotted (flathead)

The oldest and simplest drive: a single flat blade. It is cheap and universally available, but it engages on only two faces, so torque is limited and the blade easily slips out of the slot. Slotted drivers are still used in electrical work, battery terminals and low-torque applications, but they are a poor choice for assembly work.

Phillips

The cross recess, defined in ISO 8764, was actually designed to cam out under excessive torque to protect the screw and the driver. That made it forgiving in the era of hand assembly, but it also means the tip must be perfectly matched to the screw and that high torque pushes the driver out of the head. Phillips remains extremely common, especially in consumer goods and electronics.

Pozidriv

An evolution of Phillips, also covered by ISO 8764. A Pozidriv tip has additional 45° flanks that grip the screw more positively and resist cam-out, allowing higher torque with less slippage. Visually it looks like a Phillips but with extra radial lines. Do not mix the two: a Phillips tip in a Pozidriv screw will round the head quickly.

Torx (star)

Defined in ISO 10664, the Torx drive is a six-pointed star. Its full-face contact transfers torque efficiently with very little cam-out, and it tolerates higher loads than a Phillips of the same size. That is why Torx dominates power tools, automotive trim, electronics and anything assembled with a driver. For buyers it is the drive most worth specifying in Cr-V or S2 steel with a hardened, coated tip.

Hex (Allen)

Hex keys (ISO 2936) drive six-sided socket-head screws. Sold as individual L-shaped keys or folding sets, they are essential for furniture, machinery and bicycle assembly. Watch for the distinction between inch and metric sets, and for ball-end hex keys that allow an angled approach in tight spaces.

Robertson (square)

A square recess with strong, self-centring engagement. Robertson screws and drivers are standard in North American woodworking and construction. They hold the screw on the tip securely, which is why they remain popular despite limited global use.

Security and specialty drives

Where tamper-resistance matters, you will meet one-way (slotted with a ratchet face), Torx with a centre pin, spanner/nut drivers and tri-wing drives. These are specified for public installations, security fittings and warranty-voiding fasteners.

What to specify when sourcing

• Material and hardness — S2 or Cr-V shaft, tip hardened to around HRC 52–58 to resist wear and twisting.
• Drive standards — reference ISO 8764 (Phillips/Pozidriv), ISO 10664 (Torx), ISO 2936 (hex) so dimensions stay consistent.
• Magnetic or non-magnetic — magnetic tips help hold screws but must match your customer’s needs.
• Tip coating — a black oxide or similar coating improves grip in the screw head.
• Set composition — the mix of drive types and sizes should match your market, not inflate the piece count.

Bottom line

Drive type is not cosmetic; it decides torque, cam-out behaviour and which screws a tool can actually turn. Specify the drives your market uses, anchor them to the right ISO standards, and demand hardened, coated tips — and your screwdriver sets will outlast the generic competition.