PZ vs PH Screwdriver Bits — The Complete UK Guide
Pozidriv (PZ) and Phillips (PH) are the two most common cruciform screw types in the UK, and mixing them up is the single biggest cause of stripped screw heads. They look almost identical at a glance, but they have fundamentally different geometry. This guide explains exactly how they differ, how to tell them apart, and which one you need for any given job.
What’s the Difference Between PZ and PH?
Both Pozidriv and Phillips have a cross-shaped recess, but the geometry is different in a way that matters enormously when driving screws.
Phillips (PH) was designed in the 1930s with a deliberate “cam-out” feature — the bit is meant to slip out of the screw head when a certain torque is reached. This was useful for factory assembly lines where overtightening was a bigger concern than cam-out. The cross has simple, clean lines that taper to a point, and the four slots are plain with no additional markings between them.
Pozidriv (PZ) was developed in the 1960s specifically to eliminate cam-out. The cross is similar but the recess has additional small ribs (tick marks) set at 45° between the four main slots. These ribs lock the bit into the screw more securely, allowing much higher torque transfer without the bit slipping. This is why Pozidriv became the standard for wood screws and construction fasteners across Europe and the UK.
How to Tell PZ and PH Apart
The quickest way to identify a Pozidriv screw is to look for the tick marks — four small lines set at 45° between the main cross slots. If you see these extra markings, it’s Pozidriv. If the cross is plain with just the four slots and nothing between them, it’s Phillips.
| Feature | Phillips (PH) | Pozidriv (PZ) |
|---|---|---|
| Cross shape | Simple cross, tapers to a point | Cross with extra ribs at 45° |
| Tick marks | None — plain cross only | Four small lines between the cross slots |
| Cam-out | Designed to cam out at high torque | Designed to resist cam-out |
| Torque transfer | Lower — bit slips before maximum torque | Higher — bit locks in, more torque before failure |
| Common in UK? | Machine screws, electrical fittings, imports | Most wood screws, chipboard screws, construction |
| Bit marking | PH1, PH2, PH3 | PZ1, PZ2, PZ3 |
Can I Use a PH Bit in a PZ Screw (or Vice Versa)?
Technically, a PZ bit will physically fit into a PH screw — the cross shape is close enough. However, a PH bit in a PZ screw is where the problems start. The Phillips bit sits too deep, doesn’t engage the additional Pozidriv ribs, and will cam out under any significant torque. This strips the screw head and makes future removal difficult or impossible.
The short answer: always use the correct bit for the screw type. A PZ2 screw needs a PZ2 bit. A PH2 screw needs a PH2 bit. The cost of keeping both in your kit is negligible compared to the cost of stripped screws, damaged work, and wasted time.
PZ and PH Sizes — Which Size Do I Need?
Both PZ and PH bits come in three main sizes. The size you need depends on the screw size (gauge) you’re driving.
| Bit Size | Screw Gauge (approx.) | Typical Use |
|---|---|---|
| PZ1 / PH1 | No. 2 – No. 4 (2.5mm–3.5mm) | Small screws — hinges, electrical face plates, cabinet fittings |
| PZ2 / PH2 | No. 5 – No. 10 (3.5mm–5mm) | General purpose — the most common size by far |
| PZ3 / PH3 | No. 12 – No. 14 (5.5mm–6.5mm) | Large screws — heavy construction, coach screws, large timber |
PZ2 and PH2 are by far the most commonly used sizes in UK construction and DIY. If you only carry one bit size, make it a PZ2 — you’ll use it for 80% of screw-driving tasks in a typical UK project.
Why Does the UK Use Pozidriv?
Pozidriv became the dominant screw type in the UK and Europe because it was adopted by the European construction industry in the 1970s and 1980s. The superior torque transfer and cam-out resistance made it ideal for wood screws, which are driven by hand and with power tools into variable materials. Phillips remained dominant in the US, where it was already deeply established in manufacturing.
This means that if you buy screws from a UK hardware shop — Screwfix, Toolstation, B&Q, Wickes — the vast majority of wood screws, chipboard screws, and general-purpose screws will be Pozidriv. Phillips screws in the UK are mostly found in machine screws, electrical components, imported electronics, and some older fittings.
Common Scenarios: PZ or PH?
| Scenario | Likely Screw Type | Bit Needed |
|---|---|---|
| Hanging a shelf with wood screws from Screwfix | Pozidriv | PZ2 |
| Fitting a light switch or socket face plate | Phillips or Pozidriv (check the screw) | PH1 or PZ1 |
| Assembling flat-pack furniture (IKEA etc.) | Phillips (PH) or hex | PH2 or hex key |
| Decking screws | Torx (increasingly common) or Pozidriv | T25 or PZ2 |
| Screwing into plasterboard wall plugs | Pozidriv | PZ2 |
| Machine screws for metalwork | Phillips | PH2 |
| Chipboard screws for kitchen units | Pozidriv | PZ2 |
| Screws that came with imported electronics | Phillips | PH1 or PH2 |
Tips for Avoiding Stripped Screws
Using the correct PZ or PH bit is the first step, but there are a few other things that make a big difference. Always push firmly into the screw head before turning — screwdriver bits need axial pressure to stay seated, especially Phillips. Use the correct size, not just the correct type — a PZ2 bit in a PZ1 screw will wobble and strip just as badly as using the wrong type entirely. If you’re using a drill or impact driver, start on a lower torque/speed setting for the first few turns until the bit is fully seated. And if a screw head is already showing signs of stripping, stop immediately and try a fresh screw rather than forcing it.
For more on choosing the right bit for any screw type, see our complete screw-to-bit reference table. If you’re using an impact driver, make sure your bits are impact-rated — see our impact driver bits guide.
Recommended PZ and PH Bit Sets
If you’re building a bit collection from scratch, these are the sets we’d recommend for UK users. A good starting point is one dedicated PZ set and one PH set — that way you always have the right bit to hand.
Wera 855/1 TH Pozidriv Bits (PZ1, PZ2, PZ3)
Wera bits are widely regarded as the best quality screwdriver bits available. Their Pozidriv bits feature a precision-machined tip that grips exceptionally well, and the Torsion zone absorbs peak torque loads in impact drivers. The 855/1 TH range covers PZ1, PZ2, and PZ3 — everything you need for UK construction screws. Available individually or in packs of 10.
Wera 851/1 TH Phillips Bits (PH1, PH2, PH3)
The same excellent build quality as the Pozidriv range but machined for Phillips screws. Essential for machine screws, electrical fittings, and imported hardware. The TH (Torsion) version is impact-driver rated. If you only buy one PH bit, make it a PH2 — it handles 90% of Phillips screws you’ll encounter.
Makita B-54519 Impact Gold 68-Piece Set
If you want a comprehensive set that covers PZ, PH, Torx, hex, and slotted bits in one case, the Makita Impact Gold 68-piece set is hard to beat. Every bit in the set is impact-rated with Makita’s Xtreme Torsion technology, so they’re safe to use in impact drivers. Includes PZ1, PZ2, PZ3, PH1, PH2, PH3, plus a full range of Torx and hex sizes, bit holders, and nut setters.