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How to drill without snapping a bit

Updated: 2026-10-23

The bit is already in the case, and the hole is about to go wrong through heat, dust or a cable you have not looked for. How to drill without snapping a bit is a sequence: match the bit, clamp the work, keep the tip cutting, and stop for concrete, a hidden service, heavy dust, or stainless without a cobalt bit. The sets these limits come from are in the [drill bit set comparison](/hub/drilling-and-accessories/drill-bit-set). Products Compared used amazon.co.uk listings and HSE guidance, and did not run a lab test, on 21 October 2026. A qualifying purchase can earn a commission at no extra cost to you.

The bit is already in the case, and the hole is about to go wrong through heat, dust or a cable you have not looked for.

Our top picks

Bosch Bosch Expert 6-piece spade set

Best overall

Bosch Bosch Expert 6-piece spade set
6.8/10about £23.95
View offer
Bosch Bosch 34-piece X-Line

Rank 2

Bosch Bosch 34-piece X-Line
9.6/10about £10.63
View offer
Bosch Bosch PointTeQ 19-piece HSS

Alternative

Bosch Bosch PointTeQ 19-piece HSS
8.6/10about £14.12
View offer
On this page
  1. 1.Set the drill up before the bit spins
  2. 2.Drill metal so the bit cuts
  3. 3.Drill brick for a plug, not for a structural hole
  4. 4.Drill a large hole in softwood

Set the drill up before the bit spins

Clamp the work so it cannot spin with the bit. Sheet metal does not belong in your hand. Eye protection stays on. A brad point polishes brick. An HSS bit in hammer mode rubs and snaps. Grip a round shank on the plain part, not on the flutes. A 1/4 inch hex belongs in a quick-change holder, which is how the spade set here is described, not a reason to run every bit on an impact driver. On metal, a centre punch stops the tip walking. On brick, a light rotary start seats the carbide before you switch to hammer. None of these listings is an SDS bit. A spec field that says SDS-Plus, when the bullets never mention it, is not a setup instruction. If you cannot see where the cables run, that check comes before the trigger.

Drill metal so the bit cuts

A twist bit snaps or blues when it rubs. Maker UK’s hand-drill sequence is worth copying: centre-punch, clamp, slow speed, cutting fluid, pull the bit out to clear swarf, and ease off as it breaks through. Their RPM bands are that page’s guide, not a British Standard. A larger bit, and a harder metal, means slower. PointTeQ’s self-centring tip does not replace fluid on steel. Bosch’s GB TiN page, a different product, also says not to use that coated bit in aluminium. A blue tip means stop. The edge has softened. A pilot for anything much larger than 6 mm in steel keeps the big bit cutting. Hammer mode stays off. Thin sheet is a different fault: the twist bit grabs as it breaks through. That choice is the HSS drill bit or step drill page, judged by thickness.
Bosch Bosch Expert 6-piece spade set

Testsieger

Bosch Bosch Expert 6-piece spade set
6.8/10about £23.95
View offer

Drill brick for a plug, not for a structural hole

A shelf bracket in brick uses the masonry bit, hammer mode, and the diameter on the plug packet. Fastbuild sometimes puts the bit half a millimetre under the plug size. BuildWiz says the bit matches the plug. Start in rotary so the carbide seats, then switch to hammer. Clear the dust before the plug goes in. Bosch DIY’s depth rule of thumb, if you are using an anchor, is the anchor length plus about 10 mm. That is a rule of thumb, not a figure from these listings. HSE sheet CN3 covers silica dust: capture it where practicable, use RPE at UK APF 20 when RPE is required, and check for electricity, gas and water. If the route of a cable is unknown, turn the power off. Which sizes the cases contain is the drill bit set for wood, metal and masonry.

Drill a large hole in softwood

A spade bit tears the exit if you keep pushing after the point breaks through. Clamp scrap behind the work, and flip the piece when the point appears. The Bosch Expert listing says softwood and particleboard, not hardwood. If the timber is oak, stop. A 25 mm spade wants a slow speed and two hands. The impact-rated hex is not a reason to use hammer mode, or to use the bit in brick. None of the sets in this comparison is a clearly specified M35 set.

Common questions

How do I stop a small drill bit snapping?
Use a sharp bit, a clamped workpiece, and less pressure than feels efficient. On steel, add cutting fluid and pull the bit out to clear swarf. Drill a pilot before you step up to a larger size. A 2 mm bit pushed like a 6 mm bit is how mixed-set reviews end. Spare 1 mm bits do not fix the force.
Should I use hammer mode on a metal bit?
No. Hammer mode is for the masonry bit in brick or block. On HSS it chips the edge and heats the tip. Turn hammer off before you move from the wall to a steel bracket. A masonry bit left in the chuck for that bracket is the matching mistake.
What size hole do I drill for a wall plug?
The diameter printed on the plug packet. Charts disagree: some put the bit half a millimetre under the plug size, and others say the bit matches the plug. Rawlplug’s tables are not always the number on the front of the pack. Dust the hole out before the plug goes in, or the plug will spin.
Can I drill brick with the masonry bit in a mixed set?
Yes, for a plug hole in brick or block, with hammer mode and the size on the packet. It is not a kit for sustained concrete, and it does not control silica dust. HSE CN3 still asks you to capture dust, use RPE at APF 20 when RPE is required, and check for electricity, gas and water. An SDS bit for concrete is outside these cases.
When should I stop and get a professional?
Stop for structural concrete, a cable or pipe you cannot locate, heavy masonry dust with nowhere for it to go, or stainless on a safety-critical fixing when you do not have a cobalt bit and fluid. A blunt HSS bit in mild steel is a shop problem. A hole you are guessing through a party wall is not. These straight-shank bits do not become SDS bits because the drill has a hammer setting.

Related pages

Drill bit set buying guide

Best drill bit set

Drill bit set

HSS drill bit or a step drill for thin steel sheet

Home mixed drill bit set for wood, metal and masonry

Sources

Public UK sources from the research digest, plus the ISO 5468 catalogue entry cited there. Shelf prices and star lines are the amazon.co.uk figures in the display file.

  1. HSE CN3, drilling with hand-held rotary tools (retrieved 22 October 2026)
  2. HSE, cutting and sanding wood (retrieved 22 October 2026)
  3. Consumer Rights Act 2015, section 9 (retrieved 22 October 2026)
  4. GOV.UK, General Product Safety Regulations 2005 (retrieved 22 October 2026)
  5. Bosch Professional GB, metal drill bits (retrieved 22 October 2026)
  6. Bosch Professional GB, TiN HSS twist bit (retrieved 22 October 2026)
  7. Cromwell, HSS step drills (retrieved 22 October 2026)
  8. ISO 5468:2017, carbide masonry bits (retrieved 22 October 2026)