Guide written by:
John, DIYer & IT developer, Brighton
A screwdriver without a bit is about as effective as trying to use a Phillips screwdriver on a slotted screw. Torx, Pozidriv, Allen… you can tackle any screw drive with just a couple of turns of the chuck! From titanium coatings to diamond tips, read on to find the best screwdriver bits for your power tool.
- Drive type
- Diamond tips
Choose a bit tip to match your screw drive
Screwdrivers transfer force (or torque) to the screw via the screw drive. The shape and size of the screwdriver tip must correspond perfectly to the screw you are working on or you run the risk of damaging the screw.
Screwdriver bit types
Slotted screws are not very well suited to power driving as the screwdriver tip tends to slide around as soon as the tool gains any speed. These screws are found on old or specialist items. Sizes generally range from 3 to 6.5 mm.
Identified by the code PH, these bits feature a simple cross-shaped recess. Though widely used, Phillips bits tend to pop out of the screw head as the speed of the tool increases. For the most part, Phillips tips range from 0 to 3 mm in size.
These tips are designated as PZ. Do not confuse them with Philips heads at the risk of stripping the screw – and tearing your hair out in the process! PZ droves are cross-shaped with two (roughly) equal halves: there are two crosses, one of which is rotated by 45°.This shape gives the screw tip better grip. Pozidriv drives (PZ) range in size from 0 to 4 mm and are most often found on wood screws.
Torx, or star drives, are designated as T and provide very good grip. Increasing in popularity (decking screws, etc.), Torx heads are recommended for all your screwing tasks; with limited risk of slipping, you'll soon be screwdriving like a pro! Sizes generally range from T10 to T40 or up to T50 for application in car mechanics.
Resistorx or tamperproof Torx
These screw drives are star-shaped with a pin in the centre and are used for increased security and comfort during intensive DIY sessions! Resistorx screw drives are mainly found in household appliances, with sizes typically ranging from T10 to T40.
Hex or Allen
These screwdriver bits are also known as hex sockets. Hex or Allen screw drives are commonly found in flatpack furniture kits. The most common sizes range from 2 to 10.
6-point and 12-point nut setter
Six- and twelve-point nut setters are not strictly bits but rather sockets. However, they are increasingly commonly found as solid constructions (one-piece sockets).
Triangular or square
Triangular or square screw drives are not widely used and tend to be more annoying than helpful to DIYers – sometimes manufacturers can be cruel like that!
Screwdriver bit materials
Screwdriver bits vary in terms of the complexity of their design and, most importantly, their strength. Like any product, the more expensive they are, the better the quality – in theory, at least!
Screwdriver bit materials
Steel is the most widely used material for bits as it offers good value for money (provided the bits are used correctly).
If you have an impact driver, you should use impact-rated bits as other bit types may break under the force.
Titanium coated bits are more durable than steel alone. But beware: sometimes poor-quality steel is hidden beneath shiny titanium!
A fine diamond particle coating is deposited onto the tip; this process significantly increases the bit's grip.
Screwdriver bits: choosing the best length
- Shorter screwdriver bits deliver the maximum amount of torqueto the screw.
- You'll also find driver bits, extensions and even long bits designed to work on screws in deep cavities.
- The longer the screwdriver bit, the greaterthe chance of slippage.
- For this reason, it is advisable to modify the torque and the screwdriver speed (RPM) accordingly and to take care choosing the right drill or electric screwdriver before you start work.
Tips for choosing the best screwdriver bits
Opt for high-quality screwdriver bits that match the type and size of your screws. Do not forget to drill pilot holes and always use quality screws.You should also remember to adjust the torque of your cordless or electric screwdriver to protect the screwdriver bit and the screw head. This will also help you to avoid splitting wooden surfaces or damaging the screw thread if you screw into metal at high speeds. Finally, go for Torx and Pozidriv screws, if possible: the results say it all!
Screwdriver bit chart
Common bit size
Bit material for standard use
Bit material for intensive use
3 ; 4 ; 4.5 ; 5.5 ; 6 ; 6.5 (mm)
Steel, hardened steel
Diamond, Zirconium, High Chrome Vanadium Steel, Titanium
PH0, PH1, PH2, PH3, PH4
PZ0, PZ1, PZ2, PZ3, PZ4
Crosshead with ribs
T10, T15, T20, T25, T30, T40
Resistorx (or tamperproof Torx)
TT10, TT15, TT20, TT25, T30, T40
Star with pin in centre
BTR or HC
2, 3, 4, 5, 6 (mm)
Guide written by:
John, DIYer & IT developer, Brighton, 71 guides
Since I was a child, I was always interested in manual and technical works. Always fascinated by woodworking, I took advantage of my first flat as a playground. On the cards: electricity (of course, safety first!) and some partition walls; but also decorating with the help of the missus, made-to-measure furniture and little tricks to optimise the space, all the while remaining as original as possible. When the little one arrived, I started building bits and pieces for him! Lacking space, I have not got a permanent workshop and certain tools I dream about but are not part of my collection. Not to worry, I already know a lot about DIY and I have a high-tech profile that I hope will guide you in your decisions!