Furniture Screws: PH vs PZ vs TX

July 5, 2026

The essential difference between screw drive types lies in power transmission: whilst PH and PZ profiles tend to slip under high torque, the star-shaped TX profile offers positive engagement without the cam-out effect.

Anyone fastening components in cabinet making or joinery will inevitably encounter various screw heads. Using the wrong bit in a cordless driver does not just ruin the screw head, but in the worst case can also damage the workpiece if the bit slips and scratches the surface of the chipboard or decorative veneer. Choosing the right drive for wood screws and furniture screws significantly determines how efficient, effortless, and secure the installation will be.

When this choice is crucial

The decision between Phillips (PH), Pozidriv (PZ), and Torx (TX) is usually made when planning a project or purchasing fixings. When fitting hardware such as a concealed hinge or a ball bearing runner, manufacturers often specify the drive of the included screws. However, when assembling carcase panels directly, the choice rests with the fitter. Factors such as the required torque, accessibility of the fixing point, and the substrate material (soft spruce vs hard MDF) all come into play.

What is the PH drive (Phillips)?

The Phillips drive, designated by the abbreviation PH, is the classic cross-recess. It was developed in the 1930s to speed up assembly line production in the automotive industry.

Technically, the PH profile is characterised by flanks that taper downwards (conical shape). This geometry was intentionally engineered so that the bit is pushed out of the screw head at a certain resistance. This phenomenon is known as the cam-out effect. Originally, this was intended to prevent screws from being over-tightened or sheared off by machines. With modern cordless drivers featuring precise torque settings, this effect is usually undesirable because it requires high axial contact pressure from the user. Typical sizes in cabinet making are PH1 and PH2.

What is the PZ drive (Pozidriv)?

The Pozidriv drive (PZ) is the technical evolution of the Phillips cross-recess. It was designed specifically to minimise the unwanted cam-out effect.

Visually, you can recognise a PZ screw by the four additional fine star lines running diagonally between the main cross slots. The decisive technical difference lies in the flanks of the main cross: these run parallel and do not taper. As a result, the bit engages much deeper and with a better positive fit. The user needs to apply significantly less pressure to prevent slipping. Over decades, the PZ profile has established itself as the absolute standard for traditional wood screws and furniture screws (often referred to as chipboard screws). The standard size for thread diameters from 3.5 mm to 5.0 mm is the PZ2 bit.

What is the TX drive (Torx / hexalobular)?

The TX profile, technically referred to as hexalobular, represents the current state of the art in screw drives. It consists of a star-shaped, undulating contour with six rounded lobes.

The TX drive transfers force across a broad surface rather than at isolated edge points. A TX drive engages like a precision-machined gear with its mate, whereas a PH cross-recess acts more like a wedge that forces itself out of the recess under excessive force. This design completely eliminates radial forces and the cam-out effect. The installer barely needs to exert any axial pressure on the cordless driver; the tool does all the work. Modern wood screws and furniture screws for professional cabinet making are now manufactured almost exclusively with a TX drive. Common sizes include TX10, TX15 (for 3.5 mm screws), and TX20 (for 4.0 mm and 4.5 mm screws).

Differences between the drives in detail

To highlight the technical characteristics, let us compare the three profiles directly across key installation parameters:

Power transmission: With the PH drive, force is transmitted only across a very small area on the edges of the flanks, leading quickly to material deformation. PZ provides a larger contact area thanks to parallel flanks. TX offers pure surface pressure, allowing the highest torque to be transferred without damaging the screw head.
Tool and material wear: Due to continuous slipping (cam-out), PH bits and matching screw heads wear out the fastest. The bit "rounds off". PZ is noticeably more robust. TX bits and screws exhibit the lowest wear because bit and screw form a stable unit.
Required contact pressure: With PH, the user must push firmly against the screw to keep the bit seated. This is particularly tiring when working overhead or in hard-to-reach areas inside a cabinet carcase. With PZ, moderate pressure is required. With TX, simply holding the cordless driver straight is sufficient.
Centring: A TX bit centres itself almost blind when inserted into the screw head. PZ also provides good centring. PH often requires more precise alignment.

When to use PH, PZ, or TX?

The choice of drive depends heavily on the specific component and the type of joint.

Furniture fittings and adjustment work

When fitting and adjusting hinges (e.g. on a full overlay or half overlay), PH2 or PZ2 screws are still commonly found on the cross mounting plate. The adjustment screws for height, depth, and overlay on a concealed hinge are also mostly equipped with a PZ cross-recess. The reason: these screws are often turned with a manual screwdriver, for which cross-recess profiles remain the most widespread among end users.

Drawer runners and slides

When securing a full extension runner or single extension runner to the carcase side panel, Euro screws (for the System 32) or classic 3.5 mm and 4.0 mm wood screws and furniture screws are generally used. Euro screws almost always have a PZ2 drive. For standard wood screws used to fix a roller runner or undermount runner, there is a strong trend towards the TX15 drive, as it is often difficult to apply enough pressure for PZ screws in cramped cabinet interiors.

Carcase assembly and heavy-duty fixings

When joining carcase panels (e.g. side panels to base and top panels) using long screws (such as 4.0 x 50 mm), the TX drive (usually TX20) is the only sensible choice. The high torque generated when driving into MDF or solid wood would inevitably lead to stripped screw heads with PH or PZ. For driving longer wood screws and furniture screws to mount wall units, the hexalobular drive is equally indispensable.

Compatibility guidelines for the workshop

A common mistake in assembly practice is mixing up bits and screws. Never use a PH bit for a PZ screw. The PH bit has tapered flanks and does not fill the parallel-sided PZ screw recess. It only grips at four tiny points, wobbles, and ruins the screw head under minimal load.

Conversely, a PZ bit often cannot seat deeply enough into a conical PH screw due to its parallel flanks. When driving standard wood screws and furniture screws, always check beforehand whether the screw head features the fine star lines for PZ or a plain cross for PH. With TX screws, mix-ups are impossible due to the completely different shape; here, you simply need to ensure the exact size matches (e.g. TX15 vs TX20).

FAQ – Frequently asked questions about screw drives

How can I tell the difference between PH and PZ with the naked eye? The PZ screw (Pozidriv) has four additional fine lines between the four main cross slots, resembling a star. The PH screw (Phillips) has a simple, smooth cross without these intermediate lines.

Why does the bit suddenly slip when driving screws? This is usually caused by the cam-out effect on PH or PZ screws when axial contact pressure is too low or the torque on the cordless driver is set too high. Another reason is using the wrong bit (PH in PZ) or a worn-out bit.

What do designations like TX20 or PZ2 mean? These are standardised size specifications for tools and screw heads. The number on PZ (e.g. 1, 2, 3) indicates the cross-recess size. PZ2 is the standard for screws with a diameter of 3.5 mm to 5.0 mm. On TX, the number (e.g. 10, 15, 20) indicates the profile dimension of the hexalobular recess.

Can I drive a TX screw with an Allen key? No. Although both profiles share a hexagonal base structure, an Allen key (hexagon socket) is a straight hexagon with flat edges. TX (hexalobular) has an undulating, star-shaped contour. An Allen key would strip and damage the TX screw.