Screwdriver Types: Heads, Drives & Choosing the Right One

A stripped screw head is not bad luck. It is almost always the result of using the wrong driver — and in most cases the driver looked right. Pozidriv and Phillips screwdrivers appear nearly identical. JIS and Phillips are visually indistinguishable to most people. Use the wrong one under any meaningful torque and the result is a rounded, damaged recess that is now harder to remove than it was to drive.

This guide covers every drive type you are likely to encounter in Australian trade and maintenance work, how to identify each one, the correct driver sizes, and the tool types available for different applications.

Why getting the drive type right matters

Every screw drive system is designed around a specific geometry — the angle of the flanks, the number of contact points, and the degree to which the driver is designed to stay in the recess under load. When you use a driver that does not match that geometry exactly, the contact shifts from the designed bearing surfaces to the edges and corners of the recess. Under torque, those edges deform. Do it once at moderate torque and the damage is minor. Do it repeatedly, or at high torque, and the recess becomes rounded to the point where no driver — not even the correct one — can grip it.

The correct driver costs less to buy than the time it takes to extract a stripped fastener. In most cases, the correct driver is the only real fix. This guide will help you identify which one you need before you apply torque, not after.

Slotted screwdrivers

The slotted drive — a single straight slot across the screw head — is the oldest screw drive system still in widespread use. It is not common in modern construction or manufactured equipment, but it is far from obsolete. You will encounter slotted fasteners regularly in:

• Electrical switchgear, switchboards and terminal blocks
• Plumbing fittings and stopcock bodies
• Older machinery and plant equipment manufactured before cross-head drives became standard
• Vintage automotive applications
• Wood screws in older furniture and joinery

Slotted screwdrivers are sized by blade width and blade thickness. Common blade widths are 2.5mm, 3mm, 4mm, 5.5mm, and 6.5mm. The blade must fit the slot cleanly — too narrow and it rocks in the slot, concentrating force on the slot corners; too wide and the blade will score the material surrounding the screw head.

Common misconception: "Flat head screwdriver" is often used as a generic term for any non-cross screwdriver. In AU trade use, flat head and slotted are the same thing. A flat head screwdriver is not a substitute for a Pozidriv or Phillips — the geometry is wrong and the blade will cam out immediately under any load.

Phillips screwdrivers

The Phillips drive is the most widely recognised cross-head drive worldwide. It was patented by Henry F. Phillips in 1936 and adopted rapidly by the automotive manufacturing industry in North America, then globally. Phillips fasteners are still the most common cross-head drive in Australian electrical work, light construction, flat-pack furniture from non-European suppliers, and imported equipment from North America and Asia.

Phillips sizes

The PH2 handles the vast majority of everyday Phillips fasteners. A PH1 and PH2 together cover most electrical and general trade work.

The cam-out design — a feature, not a flaw

Phillips screws are deliberately designed to cam out — to eject the driver from the recess when a certain torque threshold is reached. This was not an oversight in the design. When Phillips developed the drive for automotive assembly lines in the 1930s, the goal was to prevent overtightening. The cam-out meant an air-powered assembly tool would slip rather than strip the screw once it was fully seated.

In hand-tightening applications, this design means the Phillips drive has a lower maximum torque than Pozidriv or Torx before slipping. For light-duty fastening this is not a problem. For high-torque applications — structural timber screws, decking, large machine screws — the cam-out becomes a genuine limitation. This is one reason Pozidriv and Torx have largely replaced Phillips in demanding applications.

Pozidriv screwdrivers

Pozidriv (often abbreviated PZ) was developed in the 1960s as a direct improvement on Phillips, specifically to eliminate cam-out. It is the dominant cross-head drive in European construction and manufacturing, and the standard drive on most modern Australian construction screws including Type 17 point screws, bugle head screws, decking screws, and chipboard screws supplied through Australian hardware and trade suppliers.

Pozidriv looks almost identical to Phillips at a glance. The difference is four additional ribs between the arms of the cross, set at 45° to the main cross. These ribs engage corresponding ribs in the screw recess and prevent the driver from camming out — significantly more torque can be applied before slippage occurs.

Pozidriv sizes

PZ2 is the most important size to have. It is the correct driver for the majority of screws sold through Australian trade and hardware suppliers.

Identifying a Pozidriv screwdriver

On the screwdriver shank or blade, the size is typically stamped as PZ1, PZ2, or PZ3. On the screw head itself, Pozidriv screws have four small radial marks between the arms of the cross. Phillips screws have smooth, uninterrupted arms with no secondary markings. This is the most reliable visual identification method.

Phillips vs Pozidriv: the most common mixup in Australian workshops

This confusion is responsible for more stripped screws in Australian homes and workshops than any other single factor. The two drives are not interchangeable — using Phillips in Pozidriv (or vice versa) will damage the screw recess, particularly under power-tool torque.

The issue is that a Phillips driver will physically fit into a Pozidriv recess. It engages the main cross arms and feels seated. But it does not engage the 45° ribs. Under torque, the mismatch means the driver rides up and out of the recess — stripping the corners of the cross arms in the process.

How to tell which you have:

• Look at the screw head. Four small radial lines between the cross arms = Pozidriv. No secondary marks = Phillips.
• Look at the driver. "PZ" prefix on the shank = Pozidriv. "PH" prefix = Phillips. A driver stamped with just a number and no prefix is likely Phillips.
• Feel the engagement. A correctly matched driver seats fully and feels solid. A mismatched driver rocks slightly in the recess under light pressure.

If in doubt on modern AU construction screws, use PZ2. Most timber screws, decking screws, and bugle head screws sold in Australia in the last 20 years are Pozidriv. Phillips is more common in electrical fittings and imported North American or Asian equipment.

JIS screwdrivers

JIS stands for Japanese Industrial Standard. JIS cross-head fasteners look identical to Phillips fasteners — same cross shape, no obvious external marking on most examples. The difference is internal: the JIS recess has a slightly different flank angle and a tighter fit geometry than Phillips.

JIS is the standard fastener drive used on Japanese-manufactured vehicles and motorcycles, and on Japanese appliances and electronics. In the Australian market, this is not a minor consideration. Toyota, Mazda, Honda, Subaru, Mitsubishi, Suzuki, Nissan, and Yamaha all use JIS fasteners extensively throughout their drivetrain, body, and electrical systems. Australia's vehicle fleet is dominated by Japanese makes. Any technician servicing Japanese vehicles without JIS drivers is using Phillips in JIS recesses on every fastener.

A Phillips driver will physically fit a JIS screw — which is why the problem goes unrecognised. But the angular mismatch means the Phillips driver bears on the outer corners of the recess rather than the full flank. At high torque (particularly with an impact driver), Phillips in JIS is one of the fastest ways to damage a screw head. JIS drivers sit flush, bear on the full flank, and do not slip.

Identifying JIS fasteners

JIS screws are technically marked with a small dot or dimple stamped near the cross recess. In practice, this mark is absent on many older JIS fasteners, worn off on used fasteners, or simply too small to see without looking for it specifically. The reliable identification method: if you are working on Japanese-made equipment, assume JIS and use a JIS driver.

JIS screwdriver availability in Australia

JIS screwdrivers are not stocked widely in general hardware retail. Specialist tool suppliers and online channels are the primary source. Vessel is the most widely recommended brand for JIS — a Japanese manufacturer whose screwdrivers are designed to the original JIS specification. Wiha produces JIS-compatible Picofinish precision screwdrivers for fine work. For automotive maintenance on Japanese vehicles, a JIS set is a worthwhile addition to any tool kit.

Torx screwdrivers

Torx is a six-point star-shaped drive developed by Camcar Textron in 1967. In Australia it is commonly called a "star head" or "star drive." The six-lobe geometry distributes torque across a larger bearing surface than either Phillips or Pozidriv, and the near-vertical flank angle means Torx does not cam out under any practical torque load.

Torx is now the dominant drive in automotive manufacturing, structural construction fasteners, and electronics. If you service modern vehicles — any make, any origin — Torx drivers are not optional. They are also standard on much modern machinery, white goods, and power tools.

For the deep-dive on Torx — the full T1 to T100 size chart, External Torx (E-series), Torx Plus (IP/EP), security Torx with centre pin, and how to choose between insert, impact-rated and hand-driver bits — see our dedicated Torx Bit Sizes Guide.

Torx T-size reference

T25 is the single most useful Torx to have for general AU automotive maintenance. T20 covers electrical accessories and light components. T27, T30, and T40 are needed for heavier powertrain work.

Security Torx (tamper-resistant Torx)

Security Torx — also designated TX or TR (tamper-resistant) — has a small pin in the centre of the six-lobe socket. The pin prevents a standard Torx driver from seating in the recess. Security Torx requires a driver with a corresponding hole in the tip.

Security Torx is used on public infrastructure fasteners (transit seating, playground equipment, public signage), some electronics (game consoles, some laptops), electrical metering equipment, and increasingly in automotive applications where tamper resistance is specified. A security Torx set is a worthwhile addition to any maintenance toolkit.

"Star screwdriver" — the AU terminology

In Australian hardware retail and trade conversation, "star screwdriver" and "star driver" consistently mean Torx. This is informal — it is not a product category designation — but it is widely understood. If someone asks for a star screwdriver, a Torx driver is what they need. When buying, look for the "Torx" or "T" designation on the product — "star" alone will not appear on professional tool packaging.

Hex screwdrivers

Hex drive — also called Allen drive — uses a six-sided (hexagonal) socket in the fastener head. In Australian use, "Allen key" typically refers to the L-shaped bar tool; a hex screwdriver is the same drive in a traditional screwdriver handle, with the hex bit pointing forward. Both engage the same fasteners.

Hex fasteners are extremely common in:

• Machinery and industrial equipment (socket head cap screws, grub screws)
• Flat-pack furniture — often 4mm or 5mm hex
• Bicycle components
• Plumbing fittings (hex socket grub screws in valve bodies)
• Automotive (engine and drivetrain components, particularly European vehicles)

Hex drive sizes in Australian use are primarily metric: 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm, 8mm, and 10mm are the most common. A few imperial hex sizes (3/32", 1/8", 5/32", 3/16", 1/4") still appear on older Australian plant and agricultural equipment, and on North American vehicles.

For screwdriver-form hex tools, the T-handle hex driver provides significantly better torque leverage than an L-key on larger fasteners. Wiha produces quality T-handle and screwdriver-form hex sets in metric sizes.

Robertson (square drive)

Robertson drive uses a square socket and was invented by Peter Robertson in Canada in 1908. It offers excellent cam-out resistance and is extremely common in Canada, where it is the standard for most construction screws. In Australia, Robertson drive fasteners are uncommon — most AU suppliers do not stock them as a standard product.

Where you will encounter Robertson in Australia: woodworking projects from Canadian or American sources, some American-made equipment, and occasionally in specialty fasteners. If you are working with imported North American timber connectors or framing hardware, check for a square recess before reaching for a Phillips.

Robertson drivers are sized R1 (smallest) through R4. R2 is the most common size in construction applications.

Security and specialty drives

Beyond the main drive types, a range of specialty and tamper-resistant drives exist. Most are encountered in specific contexts — consumer electronics, public infrastructure, or legacy equipment.

For most trades, Pentalobe and Tri-wing are the only specialty drives likely to appear in general work — Pentalobe on any Apple device repair, Tri-wing on Nintendo hardware. Both require their own dedicated drivers and are not addressable with any standard driver type.

Screwdriver tool types

Drive type (the recess geometry) and tool type (the handle/mechanism design) are independent variables. Every drive type is available in multiple tool types.

Screwdriver size reference

Having the right driver size is as important as having the right drive type. An oversized or undersized driver applies torque to the wrong part of the recess geometry and causes damage even when the drive type is correct.

How to read a screw head and select the right driver

Drive style (Phillips, Pozi, Torx, hex socket etc.) and head shape (pan, button, truss, countersunk etc.) are independent decisions. The same head shape — for example a pan head — can be ordered with several different drives. For the full head-shape reference covering pan, button, truss, countersunk, dome, wafer, bugle, hex flange and security heads, see our Screw Head Types Guide.

Before applying any driver to an unfamiliar fastener:

1. Identify the drive type by geometry. Count the arms (cross = Phillips, Pozidriv, or JIS; six points = Torx; single line = slotted; six-sided socket = hex). For cross-head drives, look for the 45° radial marks that indicate Pozidriv. Look for a small dot that may indicate JIS.
2. Select the correct drive type. On Japanese equipment, default to JIS. On modern Australian construction screws, default to Pozidriv. On electrical fittings, default to Phillips. If uncertain, look at the marking on an existing known-correct driver nearby.
3. Select the correct size. Seat the driver in the recess without applying torque. It should feel fully engaged with no rocking and no gap between the driver tip and the recess walls. If it rocks, the size is wrong.
4. Apply torque progressively. If the driver begins to cam out or walk, stop immediately — continuing will damage the recess. Reassess the drive type and size before proceeding.

Frequently asked questions about screwdriver types

What is the difference between Phillips and Pozidriv screwdrivers?

Phillips (PH) and Pozidriv (PZ) are both cross-head drives that look nearly identical, but they are not interchangeable. Pozidriv has four additional ribs between the arms of the cross, set at 45°, which engage matching ribs in the screw recess and prevent cam-out. Phillips was designed with shallow-angle flanks that allow the driver to cam out under high torque. Pozidriv can handle significantly more torque without slipping. Most modern Australian construction screws are Pozidriv; most electrical fittings and North American/Asian imported hardware use Phillips.

Can I use a Phillips screwdriver on a Pozidriv screw?

A Phillips driver will physically fit into a Pozidriv recess but will not engage correctly. The Phillips tip contacts the main cross arms but misses the 45° ribs. Under load, the driver will cam out and round the corners of the recess. For light hand-tightening with minimal torque, the damage is minor. Under power-tool torque, a Phillips driver in a Pozidriv screw will strip the head quickly. Use the correct PZ-sized Pozidriv driver.

How do I tell if a screw is Phillips or Pozidriv?

Look at the screw head. Pozidriv screws have four small radial lines between the arms of the cross — these correspond to the 45° ribs on the PZ driver. Phillips screws have a plain cross with no secondary markings. If the radial lines are present, the screw is Pozidriv and requires a PZ driver. If the cross is clean with no secondary marks, it is Phillips and requires a PH driver. On very small or worn screws the marks can be difficult to see — use good lighting and magnification if needed.

What is a JIS screwdriver and do I need one for Japanese cars?

JIS (Japanese Industrial Standard) is a cross-head drive used on Japanese-manufactured vehicles, motorcycles, and appliances. JIS screws look identical to Phillips and have no obvious external marker on most examples. The internal geometry is slightly different — the flank angles are tighter. A Phillips driver fits JIS screws but does not bear on the full flank, creating a cam-out risk under high torque. If you work on Japanese vehicles (Toyota, Honda, Mazda, Subaru, Mitsubishi, Suzuki, Yamaha) or motorcycles, JIS drivers will correctly engage the fasteners that a Phillips driver damages. JIS drivers are available from specialist tool suppliers; Wiha Picofinish precision drivers cover the fine-thread JIS fasteners in electronics and instruments.

What does the T-number mean on Torx screwdrivers (T8, T20, T25)?

The T-number refers to the diameter of the inscribed circle of the six-point star, in standardised increments. Higher numbers are larger drives. T8 is used in laptops and consumer electronics; T20 in light automotive and electrical accessories; T25 is the most common Torx size in Australian automotive maintenance (Toyota, Mazda, Subaru brake components, trim panels, engine covers); T27, T30, and T40 are used for heavier drivetrain and structural fasteners. Most automotive Torx sets include T20 through T50; most electronics kits include T4 through T15.

What is a "star head" screwdriver?

In Australian trade and hardware usage, "star head" or "star drive" is an informal name for Torx. The six-lobe geometry looks like a six-pointed star. This is not an official designation — you will not see "star" on professional tool packaging — but it is widely understood. If someone asks for a star driver or star screwdriver, they need a Torx driver. Check the fastener for the T-size number and match the driver accordingly.

Why does my Phillips screwdriver keep slipping out of the screw?

Three possible causes: (1) Wrong drive type — the screw may be Pozidriv or JIS, not Phillips. Check for the 45° radial marks (Pozidriv) or consider whether it is Japanese equipment (JIS). (2) Wrong size — a PH2 in a PH1 recess bridges across rather than seating fully. The driver must match the screw size. (3) Worn driver tip — Phillips tips wear with use; once the flanks are rounded, the driver cannot grip the recess properly. Replace worn drivers rather than continuing to use them.

What screwdriver does IKEA furniture use?

IKEA furniture uses Pozidriv screws, predominantly PZ2. Despite this, most Australians reach for a Phillips driver during assembly — Phillips drivers will fit but will strip the IKEA screw heads under power-tool torque. Use a PZ2 Pozidriv screwdriver or bit. The engagement with a correctly matched PZ2 is noticeably more positive than with a Phillips driver.

What is a security Torx screwdriver?

Security Torx — also called tamper-resistant Torx (TR or TX) — has a small pin in the centre of the six-lobe recess that prevents a standard Torx driver from engaging. A security Torx driver has a corresponding hollow at the tip to clear the centre pin. Security Torx is used on public infrastructure fasteners, game consoles (some models), electrical metering equipment, and some automotive applications. Standard Torx sizes in the T8–T40 range are commonly available in tamper-resistant versions.

What is the difference between an impact screwdriver and an impact driver?

A manual impact screwdriver is a hand tool struck with a hammer. The body converts the hammer blow into a rotational impulse that can free seized or corroded fasteners — particularly useful on Japanese vehicles where JIS or Phillips screws have corroded in place. An impact driver is a cordless power tool that uses an internal rotational hammering mechanism to drive fasteners at high torque with lower reaction force than a drill. These are entirely different tools. The manual impact screwdriver is a specialised extraction tool; the cordless impact driver is a primary fastening tool for construction and trade work.

What is a ratchet screwdriver used for?

A ratchet screwdriver uses a ratcheting mechanism in the handle that allows the blade to drive in one direction while the handle moves freely in the other. This means you can maintain your grip and rock the handle back and forth without repositioning — significantly faster for high-repetition work than lifting and repositioning a standard driver. Ratchet screwdrivers are used in switchboard work, assembly work, and any application involving multiple fasteners of the same type. Most ratchet screwdrivers accept interchangeable bits, so one handle covers Phillips, Pozidriv, Torx, slotted, and hex drives.

What does "cam out" mean on a screwdriver?

Cam-out describes the tendency of a driver to ride up and out of the screw recess under rotational load. It occurs when the angular geometry of the driver flanks causes an upward force component as torque increases. Phillips screws are deliberately designed to cam out at a specific torque — this was a feature for assembly-line manufacturing. Pozidriv, Torx, and Robertson drives have near-vertical flanks that resist cam-out. In practice, cam-out damages the recess — each time the driver jumps out, it rounds the contact surfaces slightly. Repeated cam-out eventually produces a screw that cannot be driven or extracted with any tool.

Screwdrivers from AIMS Industrial

AIMS Industrial stocks the full Wiha screwdriver range for trade and industrial use — including Picofinish precision drivers (Phillips, Pozidriv, Torx, slotted), SoftFinish insulated VDE 1000V drivers for electrical work, ESD-safe precision sets, torque screwdrivers from 0.04Nm to 5.0Nm, and stubby and ratchet configurations across all common drive types.

Browse screwdrivers at AIMS Industrial  |  Browse screwdriver bits at AIMS Industrial

Related guides:

• Types of Spanners: Complete Guide to Wrench & Spanner Selection
• Drill Bit Types Guide — choosing the right bit for every material
• Tap & Die Guide — cutting and repairing threads