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Spot weld cutter vs drill bit: ring or milled nugget

Updated: October 2026

You are choosing between two tools that amazon.co.uk sells under one search, and they do not remove the same metal. A spot weld cutter vs drill bit decision is a ring around the nugget, or a flat face that mills it away. Both can separate a panel if you stop at the first sheet. A crown fails when it cannot sit square. A solid bit fails when you run it through the sheet you meant to keep. The twelve listings are on the [spot weld drill comparison](/hub/drilling-and-accessories/spot-weld-drill). The Products Compared editorial team did not run a lab test. A qualifying purchase can earn a commission at no extra cost to you.

You are choosing between two tools that amazon.co.uk sells under one search, and they do not remove the same metal. A spot weld cutter vs drill bit decision is a ring around the nugget, or a flat face that mills it away.

Our top picks

Sealey Sealey AK4734 8 mm spot weld drill

Best overall

Sealey Sealey AK4734 8 mm spot weld drill
8.6/10about £7.99
View offer
BGS BGS 1632 10-piece spot weld drill set

Alternative

BGS BGS 1632 10-piece spot weld drill set
8.0/10about £16.92
View offer
Gasea Gasea 6 mm and 8 mm spot weld bits

Best value

Gasea Gasea 6 mm and 8 mm spot weld bits
7.1/10about £7.79
View offer
On this page
  1. 1.What each tool removes
  2. 2.When the crown is the better shape
  3. 3.When the solid bit is the better shape
  4. 4.One recommendation with a condition

What each tool removes

A crown cuts a ring and leaves the middle of the weld standing. Laser Tools describes a 9.5 mm double-ended head on a spring pin: you drill a shallow pilot, the pin sits in it, and you stop when the top panel pops. Keep drilling after the pop and the ring becomes a hole in the sheet you meant to keep. A solid bit mills the nugget. On the same page the other tool is an 8 mm high-speed-steel bit with 5% cobalt and a flat face. There is no button, so going through leaves an 8 mm hole in the second panel. Basic Welding lists Laser's 7048 set at £36.45 with both shapes in one case. That set is not an ASIN here.

When the crown is the better shape

Choose a crown when you can hold it square and spare heads matter more than one milled hole. Cock the crown and the teeth walk. Topcloud's UK reviews describe that walk until you centre-punch, and stripped threads when the angle is wrong. The BGS 1632, at about £16.92, states 9.5 mm crowns, an 8 by 80 mm drill, and 700 to 2000 rpm. It follows the Laser pattern, and it is not the Laser box. The Topcloud nine-piece kit, at about £12.96, is titled 3/8 inch and states no millimetres and no speed. 3/8 inch is 9.525 mm, which is not a reason to relabel Topcloud as 9.5 mm. Square-on welds are the crown's job.
Sealey Sealey AK4734 8 mm spot weld drill

Testsieger

Sealey Sealey AK4734 8 mm spot weld drill
8.6/10about £7.99
View offer

When the solid bit is the better shape

Choose a solid bit when you want to mill the nugget and you can stop at the first sheet, especially where you cannot get 90 degrees. Tight inner wings and bracket feet are where a flat face reaches and a crown cannot sit down. In this set that bit is the Sealey AK4734, about £7.99, 8 by 80 mm, HSS with 5% cobalt. On The Mini Forum, several restorers prefer the flat cobalt bit and call small hole-cutters poor. A December 2025 MIG Welding Forum note says a hole-cutter type did not last. Topcloud reviews also include punched crowns that did the job. A 10 mm solid bit is a larger milled hole, not a 3/8 inch crown.

One recommendation with a condition

Start with a solid 8 mm spot-weld bit when you are keeping the lower flange and the weld sits at a tight angle. In this set that bit is the Sealey AK4734 at about £7.99. Add a crown when the welds are square-on: BGS 1632 at about £16.92 if you need 9.5 mm and 700 to 2000 rpm in writing, or Topcloud at about £12.96 if you accept a 3/8 inch title with no millimetres. Laser 7048 at £36.45 holds both shapes and is not one of these twelve listings. Boron steel is outside both choices.

Common questions

What does a crown cut that a solid bit does not?
A crown cuts a ring and leaves a button of weld, which you dress after the skin is off. A solid bit mills the nugget, so the hole matches the bit and there is no button. Laser Tools describes both: a 9.5 mm head on a spring pin, and an 8 mm cobalt bit. You still stop when the top sheet releases.
When is the solid bit the better reach?
When the weld is at a tight angle and you cannot sit a crown flat at 90 degrees. A spring-pin cutter walks if it is cocked, which Topcloud's UK reviews describe, along with stripped threads. A flat 8 mm bit can mill that nugget if you stop at the first sheet. In this set that bit is the Sealey AK4734. On a wide, square flange where you wanted a ring and spare heads, the crown is the closer match.
Why do some UK restorers reject hole-cutter styles?
On The Mini Forum, several restorers prefer a flat cobalt bit and call small hole-cutters poor. A December 2025 MIG Welding Forum thread has one user saying a hole-cutter type did not last. That is owner opinion, not a test. Topcloud reviews include crown kits that worked after a centre punch. Use the warning when you cannot hold the cutter square. It is not proof that every crown fails.
Can one kit honestly contain both?
Yes, when the contents line names a crown and a solid bit. Laser 7048, listed at £36.45 by Basic Welding, has 9.5 mm heads and one 8 mm cobalt bit. The BGS 1632 is the in-set version of that pattern, at about £16.92. Hole openers in the same tin are not spare crowns.
Does 3/8 inch on the Topcloud title equal the BGS 9.5 mm?
No. Three-eighths of an inch is 9.525 mm, and Topcloud states no millimetres, so you cannot relabel that kit as 9.5 mm. BGS prints 9.5 mm. Ten millimetres is a different solid size, not a 3/8 inch crown.

Related pages

How to use a spot weld drill

Spot weld drill buying guide

Best spot weld drill

Spot weld drill

Drill spot welds on a car panel and know the limit

Sources

Public UK sources used for this comparison. Listing prices are from amazon.co.uk on 15 October 2026.

  1. Laser Tools — spot weld cutters and drills (retrieved 15 October 2026)
  2. Sealey AK4734 HSS cobalt spot weld drill bit 8 mm (retrieved 15 October 2026)
  3. Mig Tig Arc — 8 mm spot weld drill bit (retrieved 15 October 2026)
  4. HSE — PUWER overview (retrieved 15 October 2026)
  5. HSE EIS16 — glove entanglement (retrieved 15 October 2026)
  6. HSE — using the right type of PPE (retrieved 15 October 2026)
  7. Consumer Rights Act 2015, section 9 (retrieved 15 October 2026)
  8. GOV.UK — General Product Safety Regulations 2005, Great Britain (retrieved 15 October 2026)