What is the difference between Phillips and Pozi screw heads?
Phillips vs. Pozi screw heads. While at first glance a Pozi head screw might look like a flat head Phillips head screw, there are distinct differences. We’ve put together this guide to explain what those differences are and the advantages of each. We’ll cover:
What are Phillips screw heads?
Phillips screws feature a cross-shaped indentation on the top of the screw head, as shown here. The cross shape of the indentation is symmetrical, with four arms of equal length that taper towards the centre. This self-centering design allows the screwdriver to apply a significant amount of torque to the screw without slipping out of the head – a common problem with slotted flathead screws, which feature a single slot, or groove, on the head.
Phillips screws are mostly used in electronics, automotive and construction.
Types of Phillips screw heads
Phillips screws are used, naturally, with a Phillips screwdriver. “Phillips” actually refers to the drive – the cross shape – not the head. The head can come in different shapes, as these examples illustrate.
This is a flat head Phillips screw, made of nylon. The difference between this flat head Phillips head screw and a slotted flathead is the drive. The Phillips drive enables quick assembly at an industrial scale. The flat head Phillips screw sits flush with the surface it’s driven into so that it doesn’t snag skin or clothes.
This nylon pan machine screw has a Phillips drive, also known as a cross drive. A pan head Phillips screw has a wide, slightly raised, or domed, head with a flat underside. It’s smooth with no sharp edges, for safety. This particular pan head Phillips screw is ideal for machinery and automotive parts and accessories, such as headlights.
This cross drive mushroom screw – also known as a Phillips truss head screw – has a wide, but low, profile to deter tampering of the assembly. It’s another type of machine screw. Its wide head provides a larger bearing surface while providing an aesthetic finish. This Phillips truss head screw is commonly used to join sheet metal together.
The Pozidriv screw head, or Pozidrive screw, is the abbreviation or acronym for "positive drive." Phillips vs. Pozi screw heads depends on where you live. Known as a Pozi screw head, or a Pozi head screw, it’s more commonly used in Europe while the U.S. favours the Phillips screw head.
The Pozi head screw is similar to a Phillips screw head but has some distinct differences. It features a cross-shaped indentation on the top of the screw head, like the Phillips screw head. However, the Pozi head screw has an additional set of smaller indentations at the corners of the main cross shape, arranged at 45-degree angles.
This additional feature is designed to provide better grip and prevent the screwdriver from slipping out of the screw head, especially at higher torques.
Types of Pozi screw heads
Because of its design, some Pozi screw heads, such as Pozi machines screws, are ideal for heavy-duty applications. You can learn more about machine screws in our Guide to machine screws.
The examples here are very much like the Phillips pan head screws, except for the drive.
This is a Pozi head chipboard screw. Specifically, it’s a type of pan head screw, meaning the head is slightly domed and has a flat underside. The Pozi head chipboard screw is a general-purpose wood screw, hence the word “chipboard.” It’s used in carpentry, cabinets, doors, furniture assembly and other applications involving wood.
A Pozi slot pan head screw – by Pozi slot, we mean drive – is also a pan head screw. The combination of the Pozi drive and the pan head makes these screws versatile and suitable for a wide range of applications. The Pozi slot pan head screw is typically used in woodworking, construction, furniture assembly, and in the electronics industry for securing components and mounting circuit boards.
Phillips vs. Pozi screw heads
How do they compare?
Pozidriv screwdrivers only fit Pozi screw drives, while it is possible to use a Phillips screwdriver with either a Phillips or Pozi screw drive. That said, a Phillips screwdriver can eventually round off the recess of the Pozi head, damaging the screw. For best results, use the proper screwdriver with their respective screws.
As already mentioned, Phillips screw heads prevent camming out – but if too much torque is applied, it will slip out, and it’s designed to do that. The reason: this prevents a power tool from twisting off the screw head. Keep in mind that removing a stripped Phillips head screw is incredibly difficult.
A Pozi head screw, on the other hand, is designed to never cam out. These screws are a progression:
- First we had the flathead slotted screw, where it’s easy for the flathead screwdriver to slip out.
- The Phillips screw head came along in the 1930s, designed as an improvement on the flathead’s susceptibility to camming.
- The Pozi head screw was introduced in the 1960s – by the Phillips Screw Company in a joint venture – as an improvement on the Phillips screw head.
Better stability
The Pozi drive was not solely created for high-torque applications. One of its main objectives was to improve stability and reduce cam out during use. In comparison to the Phillips design, the Pozi drive features parallel flutes at the tip of the driver. This is an improvement from the tapered flutes used in the Phillips design, which had a tendency to encourage disengagement due to their sloped shape. Parallel flutes provide better locking functionality, resulting in reduced disengagement from the driver and better overall performance.
You might find it helpful to learn about other screw types in our guide, What are screw heads, drives and threads?
At a glance: Phillips vs. Pozi screw heads
| Phillips head screw | Pozi head screw | |
|---|---|---|
| Cross-shaped slot | Yes | Yes |
| Drive shape | 4 radial points | 8 radial points |
| Susceptible to cam out | Slight | No |
| Grip/stability to prevent camming out | Good | Best |
| Flutes | Tapered | Parallel |
The advantages of Phillips screw heads
Reasons to consider using Phillips screw heads:
| Characteristic | Definition |
|---|---|
| Easy to use | Designed ease of use compared to most other screws, such as slotted heads, which require precise alignment between the screwdriver and the screw. The self-centering feature of Phillips screw heads allows the screwdriver to insert into the screw head at an angle. The screw can still tighten or loosen. |
| More torque | Can apply more torque to Phillips screws than other types of screw heads. This is because the four arms of the cross-shaped indentation are tapered, which helps the screwdriver maintain a good grip on the screw. |
| Resistance to cam out | Cam-out occurs when the screwdriver slips out of the screw head due to too much torque being applied. Phillips screw heads resist cam-out, reducing the likelihood of damage to the screw or the surrounding material. |
| Availability | Widely available in all regions, making them a convenient choice. |
The advantages of Pozi screw heads
Why should you consider using Pozi screw heads? There are several advantages compared to other screws.
| Characteristic | Definition |
|---|---|
| Better grip | Additional set of smaller indentations at the corners of the main cross shape provides better grip, reducing the likelihood of the Ponzidriv screwdriver slipping out of the screw head. |
| Reduced cam-out | Improved grip of Pozi screw heads helps reduce the likelihood of cam out. |
| Increased torque | Steep angle provides more torque and generally makes them better suited for high-stress applications. |
| Improved accuracy | The precise fit of Pozi screw heads with Pozidriv screwdrivers ensures a secure and accurate fit, reducing the risk of damage to the screw head or surrounding material. |
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