DIY Basics & Hand Tools · 8 min read · Beginner

Screw Heads & Screwdriver Bits Explained: Flat, Phillips, Pozidriv & Torx

Identify common screw-drive profiles, choose the matching bit and reduce stripped or damaged screw heads.

Key points & steps

Look at the screw recess before choosing a tool. Slotted/flat screws have one straight slot; Phillips (PH) and Pozidriv (PZ) are cross-head systems; Torx uses a six-lobed star-shaped recess.
Match both the drive family and the bit size. A bit that is the wrong size can wobble, climb out of the recess and damage the screw even if the general shape looks similar.
Do not treat Phillips and Pozidriv as interchangeable. They are different profiles; using the wrong one increases the chance of cam-out and damaged recesses.
Pozidriv screws are often identifiable by the additional small marks/ribs between the four main cross slots, but markings vary, so use the screw/fastener specification where available.
PZ2 is particularly common on general-purpose UK woodscrews, but never assume PZ2 purely from screw diameter—check the recess and packaging.
Keep the driver aligned with the screw axis and apply enough forward pressure to keep the bit fully seated while driving.
Stop when the bit starts slipping repeatedly. Replace a worn bit or choose the correct profile instead of increasing force.

A correctly fitting bit should sit positively in the recess with very little side-to-side movement.
Damaged screws are often easier to avoid than remove: use a fresh bit before the recess is rounded out.
Impact drivers can apply high torque quickly, so correct bit fit matters even more.