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Drill bit buying guide

Updated: 2026-10-23

You already own a drill, and the box leads with a piece count and a gold finish. That does not say whether the hole is in brick, mild steel or plasterboard. This drill bit buying guide walks the order that decides the set: the material, the diameter in millimetres, the shank, the steel, and only then the case. The ten amazon.co.uk listings, from £5.95 to £37.89, sit in the [drill bit comparison](/hub/drilling-and-accessories/drill-bit). Products Compared used those listings and public UK guides on 22 October 2026, and did not run a lab test. A qualifying purchase can earn a commission at no extra cost to you.

You already own a drill, and the box leads with a piece count and a gold finish. That does not say whether the hole is in brick, mild steel or plasterboard.

Our top picks

Bosch Bosch 34-piece X-Line

Best overall

Bosch Bosch 34-piece X-Line
9.4/10about £10.63
View offer
Bosch Bosch 70-piece X-Line

Alternative

Bosch Bosch 70-piece X-Line
9.1/10about £20.99
View offer
Bosch Bosch Mini X-Line 15-piece

Best value

Bosch Bosch Mini X-Line 15-piece
9.4/10about £7.99
View offer
On this page
  1. 1.Start with the material of the hole
  2. 2.Take the diameter from the screw or the plug pack
  3. 3.Match the shank to the chuck
  4. 4.Read the steel, not the colour
  5. 5.Then look at the case and the piece count

Start with the material of the hole

A twist bit is a family, not a universal cutter. Wood wants a brad point. Mild steel and aluminium want high-speed steel, in rotation only. Stainless wants the listing that says cobalt. Brick wants a carbide tip, sometimes labelled CYL-1, with hammer mode on. The Mini X-Line at £7.99 is five HSS, five carbide masonry and five wood bits at 3, 4, 5, 6 and 8 mm. PointTeQ at £14.12 names mild steel and leaves masonry out. A 4.7-star rating does not fill a missing size. Speed and oil sit on the how to use a drill bit page.

Take the diameter from the screw or the plug pack

Bosch DIY UK's wood example is a 3 mm bit for a 3.5 mm screw, a pilot rather than a clearance hole. For a wall anchor, the bit and the anchor share a diameter, and the pack beats a colour chart. The Mini repeats 3, 4, 5, 6 and 8 mm, so 5.5 mm and 7 mm are missing. The 34-piece lists CYL-1 masonry at 5, 5.5, 6, 7 and 8 mm, and its metal bits stop at 5 mm. The 50-piece lists masonry to 10 mm with no 5.5 mm. The 70-piece says six masonry bits from 4 to 10 mm without listing each one. A 6 mm hole in brick and a 6 mm hole in mild steel are two bits.
Bosch Bosch 34-piece X-Line

Testsieger

Bosch Bosch 34-piece X-Line
9.4/10about £10.63
View offer

Match the shank to the chuck

A round or cylindrical shank belongs in a three-jaw chuck. A 1/4 inch hex belongs in a quick-change holder. None of these ten listings is SDS. The Mini, Amazon Basics, PointTeQ and LSLANSOON state a cylindrical, straight or round shank. The X-Line cases say cylindrical and hex because the screwdriver bits are hex. Amtech F1120 at £5.95 is the hex drill-bit set, title sizes 1.5–6.5 mm, and the bullets do not call it impact-rated. STROTON does not state a shank. PointTeQ mentions a reduced shank and does not say which sizes are reduced.

Read the steel, not the colour

High-speed steel covers mild steel and aluminium. Screwfix treats cobalt as the alloy for stainless, and titanium nitride as a wear coating. A gold coat is still HSS. Amtech's title says titanium-nitride HSS and the spec says alloy steel. Amazon Basics says titanium in the title and polished in the finish field. The 34-piece metal bits stop at 5 mm. LSLANSOON prints 118 degrees in a bullet and 1183 degrees in the spec. STROTON is the only listing that says M42 8% cobalt. Why that is the wrong spend for brick is the HSS or cobalt drill bits page.

Then look at the case and the piece count

The 70-piece X-Line at £20.99 is the clearest trap. Inside are eleven HSS-TiN metal bits to 6.5 mm, six masonry bits from 4 to 10 mm, five wood bits and spade bits at 16, 22 and 32 mm. The rest is 24 bits at 25 mm, 10 at 50 mm and seven nutsetters. The 34-piece prints wood sizes as 4/5/6/78 mm and also says 4 to 8 mm.

Common questions

Does a higher piece count mean more drill bits?
Often it means more screwdriver bits. The Bosch 70-piece X-Line at £20.99 includes eleven metal bits, six masonry bits, five wood bits and three spade bits, and a large share of the 70 is 25 mm and 50 mm driver bits plus nutsetters. The number-of-pieces field on that listing says 1.
Is a gold or titanium drill bit the same as cobalt?
No. Titanium nitride is a coating on high-speed steel. Cobalt is an alloy in the steel. On these amazon.co.uk listings, the gold Bosch, Amtech, Amazon Basics and LSLANSOON sets stay in the HSS group. The only set that says M42 8% cobalt is STROTON at £37.89.
Which shank fits a normal drill chuck?
A round, straight or cylindrical shank fits a three-jaw chuck on a combi drill. A 1/4 inch hex fits a quick-change holder, which is the Amtech F1120 shape, in title sizes 1.5–6.5 mm. The mixed X-Line cases include both, because the screwdriver bits are hex. None of these listings is SDS-plus.
What size drill bit do I need for a screw or a wall plug?
For a wood screw, Bosch DIY UK's example is a 3 mm bit for a 3.5 mm screw. For a wall anchor, the bit and the anchor should share a diameter, and the pack in your hand wins over a colour chart. The Mini X-Line has 3, 4, 5, 6 and 8 mm. The 34-piece names a 5.5 mm masonry bit.
When is a step bit or a cobalt set the right buy instead?
Buy the LSLANSOON five-piece at £12.99 when the job is several diameters in thin sheet, wood or plastic, and the steps are not listed one by one. Buy STROTON when the hole is stainless and the listing's M42 line is what you came for. Leave both of them in the drawer for a brick plug.

Related pages

Best drill bits

Masonry drill bit

Drill bit

How to use a drill bit: speed, oil, dust and cables

HSS or cobalt drill bits for mild steel or stainless

Sources

Public UK sources from the research digest. Shelf prices and star lines are the amazon.co.uk figures in the display file.

  1. HSE CN3: silica dust and APF 20 (retrieved 22 October 2026)
  2. HSE CIS36: drilling and respirable crystalline silica (retrieved 22 October 2026)
  3. HSE: electricity, drilling near cables (retrieved 22 October 2026)
  4. HSE CIS65: power off if cable routes are unknown (retrieved 22 October 2026)
  5. Bosch DIY UK: guide to drills (retrieved 22 October 2026)
  6. Screwfix: guide to types of drill bits (retrieved 22 October 2026)
  7. Rawlplug UNO universal plug (retrieved 22 October 2026)
  8. CMT: standard plastic wall plugs (retrieved 22 October 2026)