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How to drill out spot welds and stop at the first sheet

Updated: October 2026

You already own a drill and a spot-weld cutter, and the panel is still on the car. The cutter either skates across the paint or keeps going through the sheet you meant to keep. This is how to drill out spot welds with the tool in your hand: punch the centre, hold the cutter square, and stop when the top sheet lets go. The twelve listings sit on the [spot weld drill comparison](/hub/drilling-and-accessories/spot-weld-drill). The Products Compared editorial team compared those amazon.co.uk listings and public UK sources on 15 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 a spot-weld cutter, and the panel is still on the car. The cutter either skates across the paint or keeps going through the sheet you meant to keep.

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.Find the weld and punch it
  2. 2.Speed, pressure, and heat
  3. 3.Stop at the first sheet, then split the joint
  4. 4.When you stop and call a body shop

Find the weld and punch it

Start where you can see the nugget. A cutter that starts on a slope will walk. Clear only enough paint to see the centre, then punch a dimple before the drill turns. Mig Tig Arc's notes for the Sealey 8 mm bit put that punch first. A 2 mm dimple on the MIG Welding Forum is one person's method, not a size printed on these bits. A crown needs the shallow pilot Laser Tools describes, so the spring pin has a seat. You are not opening the second sheet with that pilot. If the flange flexes, the cutter cocks and the teeth shear.

Speed, pressure, and heat

Run only as fast as you can keep the cutter square, with light pressure. Mig Tig Arc's wording for that 8 mm bit is slow to medium on a variable-speed drill. No rpm is printed there, so do not invent one for the Sealey bit. The only stated speed in this set is the BGS 1632, at 700 to 2000 rpm, and that band stays on that set. Wielander+Schill cap their WS90 at 1200 rpm. That machine is not a handheld bit here, so do not copy 1200 rpm onto the Sealey bit. Do not claim any oil makes a cutter last three to five times longer. If the joint is heating, ease off before the second sheet is holed.
Sealey Sealey AK4734 8 mm spot weld drill

Testsieger

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

Stop at the first sheet, then split the joint

Stop when the top sheet releases. Laser Tools describes the panel letting go around the pin. Mig Tig Arc's order is the same: cut the weld in the skin you are removing, split the joint with a thin chisel or a seam splitter, then dress what is left. A light witness mark can still be a successful stop. Daylight through both sheets is not, and Topcloud's UK reviews include cutters driven through both panels by pressure. Lever before the nugget is cut and you tear the flange you hoped to reuse. If the panels will not part, look for a missed weld before you add force. Teeth shear when the crown is cocked, which Topcloud's UK reviews match with stripped arbor threads. Wear eye protection while the bit turns, and keep gloves off the hand near the chuck. That follows the Health and Safety Executive's PPE guidance and the EIS16 entanglement warning. Change a crown only with the drill stopped.

When you stop and call a body shop

Mild steel is what Mig Tig Arc names for that 8 mm bit, and the same page says it is not for boron. Sealey's high-stress line for the AK4734 is not a boron approval. An Amazon cell that says Boron clashes with the product text. Wielander+Schill's boron setup is their own drill and a tungsten-carbide bit, not an HSS bit from this shelf. Hand the flange to a body shop when the joint is structural, when the vehicle information names boron or ultra-high-strength steel, when the weld sits near fuel, brakes, or an airbag, or when the flange is already torn and still has to carry load. PUWER 1998 applies when the drill is work equipment. A hobby garage is not a bodyshop's duty.

Common questions

Do you centre-punch before a spot-weld bit?
Yes. Punch a dimple in the centre of the weld before the cutter turns, so the point or the pilot has a seat. Mig Tig Arc puts that punch first for an 8 mm bit. A 2 mm dimple on the MIG Welding Forum is one person's method, not a printed size. A crown still needs the shallow pilot Laser Tools describes. That pilot is not a hole through the second sheet.
What speed do you use if the listing does not state one?
Use a slow to medium speed and light pressure. That is Mig Tig Arc's wording where no rpm is printed. Do not copy another product's number onto a blank listing. The BGS 1632 is the only set here with a stated speed, 700 to 2000 rpm, and that figure stays on that set. Wielander+Schill's 1200 rpm ceiling belongs to their WS90.
When do you stop so the second sheet survives?
Stop when the top sheet releases. Laser Tools treats that release as the moment you come off the trigger. A witness mark can mean you stopped in time, and daylight through both sheets means the cut ran on. If you cannot hold the cutter square, stop before you chase it.
Does cutting oil belong in the steps?
UK forum users mention cutting paste, and Wielander+Schill specify cutting oil for their own machine. A Sealey reviewer used WD-40, which is that reviewer's method, not a packet rule. Do not claim a lubricant multiplies cutter life by three to five times. Oil will not save a cutter that is cocked off the panel.
Why do teeth snap?
Teeth shear when the cutter is not square to the sheet. That is the MIG Welding Forum's account, and it matches Topcloud reviews in which a cocked crown walks or strips arbor threads. A centre punch and a supported panel keep you square. Change a damaged head with the drill stopped.

Related pages

Spot weld drill for car panels

Spot weld cutter vs bit

Spot weld drill buying guide

Spot weld drill

Best spot weld drill bit: which listing fits the job

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)