How to use a universal drill bit
Updated: October 2026
You already have a bit in the chuck, a pencil mark on a UK wall, and a 6 mm plug in the other hand. The mistakes that spoil the hole are a hammer setting copied from the wrong guide, a hex bit left in an impact driver the packet never rated, and a hole that is the right diameter but too shallow. This page is the sequence and the stop line. It does not pick a winner. How to use a universal drill bit starts with the wall, then the plug, then the mode on the packet. Which bit you should own is on the [universal drill bit comparison](/hub/drilling-and-accessories/universal-drill-bit).
You already have a bit in the chuck, a pencil mark on a UK wall, and a 6 mm plug in the other hand.
You already have a bit in the chuck, a pencil mark on a UK wall, and a 6 mm plug in the other hand. The mistakes that spoil the hole are a hammer setting copied from the wrong guide, a hex bit left in an impact driver the packet never rated, and a hole that is the right diameter but too shallow. This page is the sequence and the stop line. It does not pick a winner. How to use a universal drill bit starts with the wall, then the plug, then the mode on the packet. Which bit you should own is on the universal drill bit comparison.
Our top picks
| Badge | Product | Impact or hammer | Shank | Bit type | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Bosch Bosch 34-piece X-Line | Not stated | Cylindrical and hex | Mixed specialist set | 8.4 | about £10.63 | View offer |
 fischer fischer D-U Hex 6 mm | Rotary and impact; cordless impact wrench | Hex | Carbide multi-material | 9.0 | about £3.48 | View offer | |
| Alternative |  Amtech Amtech 13-piece HSS hex set | Not stated. Reviews conflict. | Hex, 1/4 inch | HSS set | 4.8 | about £5.95 | View offer |
On this page
Before the bit turns
Find out what is in the wall before the bit touches it. Electrical Safety First and the Health and Safety Executive sit behind the same household rule: use a detector, check both sides where you can, and stop if you are not sure a cable or a pipe is clear. Move the mark rather than drilling just shallow. Homes built or refurbished before 2000 can still hide asbestos. GOV.UK advice is not to drill material you suspect. If you cannot tell what the sheet is, that is where a professional replaces a cordless drill. Eye protection stays on while you clear dust.
Diameter and depth
Match the drill to the plug, not to a screw you hope will feel tight. Be Practical and Screwfix agree that a 6 mm plug needs a 6 mm hole, and most red plugs are 6 mm. B&Q puts the screw about 1–2 mm smaller than the plug, so a 4 mm or 5 mm screw is the usual partner. A 6 mm screw forced into that plug is how the plug spins.
Tape the bit a little deeper than the plug, which is B&Q’s method, so the plug sits flush and the screw still has room. Start square, with light pressure, and do not select hammer for that first touch. Shank and type were the buying guide.
Speed, feed, and hammer
The hammer setting comes from the bit maker, not from the fact the wall is brick. B&Q’s hammer-for-brick line sits beside a masonry bit, not beside every universal bit. Be Practical assumes a masonry bit for brick, concrete or stone, and HSS for plasterboard. Mode is per bit. A Faithfull multi-construction bit sold in the UK is rotary or hammer depending on the material, and rotary only in 4 mm. The fischer D-U Hex listing says rotary and impact. ITS says use rotary if you want that kind of tip to last. If your packet says rotary only, do not copy the fischer line onto it. Keep speed low until the tip has bitten. A 1/4 inch hex click in an impact driver is a fit, not a rating.
Tile, dust, and the stop line
Glaze is not brick, even when the bit claims both. Hammer stays off on tile. Screwfix and Bosch Professional both say rotary only, and Bosch treats a whistle as rubbing rather than cutting. The Tile Association adds masking tape, low speed, and diamond for porcelain. If the glaze cracks, change bit.
Clear dust before the plug goes in, or it feels tight and then spins. At work, masonry dust follows HSE note CN3. Two plug holes at home are not that duty. The dust is still not harmless.
Written by the Products Compared editorial team, updated 15 October 2026, from public UK guides and the listing wording we compared. No lab test. A qualifying purchase through our links can earn us a commission at no extra cost to you.
Common questions
What size hole does a 6 mm plug need?
A 6 mm plug needs a 6 mm hole. Be Practical states that match, and Screwfix treats most red plugs as 6 mm. B&Q suggests a screw about 1–2 mm smaller than the plug, so a 4 mm or 5 mm screw is the usual partner. A 5 mm hole crushes a 6 mm plug or leaves it proud. An 8 mm hole leaves it spinning. If the plug packet disagrees, follow the packet.
How deep should the hole be?
Deeper than the plug, by a margin you can see. B&Q’s method is tape on the bit slightly longer than the plug, so the plug sits flush and the screw still bites. If you stop when the plastic disappears, the plug bottoms out. Longer plugs need a longer hole. The tape is the depth stop a household drill does not have.
How do you stop the bit skating on tile?
Keep hammer off, use a low speed, and give the tip a bite. The Tile Association suggests masking tape. Bosch Professional says a whistle means the bit is rubbing, so ease off instead of pressing harder. A square, light start matters more than force. Porcelain wants a diamond bit in that Tile Association guide. A universal carbide claim is not a substitute.
Can you leave the bit in an impact driver?
Only when that bit is rated for it. A 1/4 inch hex fits the collet, and the fit is not the rating. The fischer D-U Hex listing says rotary and impact. Other hex sets in this comparison do not state an impact rating. Screwfix’s impact-driver guide is about driving fasteners, not drilling masonry. If the packet is silent, use a combi chuck.
When do you stop and fetch help?
Stop if you suspect a cable, a pipe or asbestos, or if the bit snaps, walks or only whistles. Stop on porcelain if you have no diamond bit, and stop if you are forcing masonry the bit is not cutting. Two holes at home are not a workplace silica job under HSE CN3, and the dust is still a reason not to breathe it. Unsure means you do not continue and hope.
Related pages
Sources
Public UK sources and the amazon.co.uk listings for these ten ASINs. Retrieved 16 October 2026.
- fischer UK, universal drill bit D-U Hex (retrieved 16 October 2026)
- Bosch DIY, guide to drills (retrieved 16 October 2026)
- B&Q, how to choose the right drill bits (retrieved 16 October 2026)
- Screwfix, guide to types of drill bits (retrieved 16 October 2026)
- ITS, types of drill bit explained (retrieved 16 October 2026)
- HSE, CN3 construction dust and silica (retrieved 16 October 2026)
- GOV.UK, asbestos in buildings (retrieved 16 October 2026)
- Electrical Safety First, DIY and cables (retrieved 16 October 2026)