How to use a spade bit
Updated: 2026-10-23
The board is marked, and the exit face is the side you will see or the side a cable has to pass cleanly. Keep the work still, clear the chips before they burn, and do not let the back of the timber burst. A flat bit leaves a functional hole, enough in a stud and a problem on a visible face if you push straight through. This page assumes the bit is already chosen. The twelve rows are on the [spade bit comparison](/hub/drilling-and-accessories/spade-bit). If the timber is a floor joist, the zone comes before any step below.
The board is marked, and the exit face is the side you will see or the side a cable has to pass cleanly. Keep the work still, clear the chips before they burn, and do not let the back of the timber burst.
The board is marked, and the exit face is the side you will see or the side a cable has to pass cleanly. Keep the work still, clear the chips before they burn, and do not let the back of the timber burst. A flat bit leaves a functional hole, enough in a stud and a problem on a visible face if you push straight through. This page assumes the bit is already chosen. The twelve rows are on the spade bit comparison. If the timber is a floor joist, the zone comes before any step below.
Our top picks
| Badge | Product | Format | Impact note | Stated materials | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Bosch Bosch Expert SelfCut Speed set | Self-feeding set | Impact-rated hex for an impact driver and a drill driver. Not hammer mode. | Softwood and particleboard. Bullets: not suitable for hardwood. | 7.2 | about £22.50 | View offer |
 SHALL SHALL 8-piece spade bit set | Set | Not printed. One review used an impact driver. | Wood | 8.1 | about £10.99 | View offer | |
| Best value |  Gunpla Gunpla 6-piece spade bit set | Set | Reviews say the hex fits an impact driver. The listing does not say impact-rated. | Plywood, plastics and chipboard in the title. Surface cell: Metal, Wood. | 7.3 | about £6.98 | View offer |
On this page
Mark, clamp, and keep the shank square
Mark the centre. The point locates the hole, and a bent point is a reason to stop. Clamp the work and put scrap behind it so the point does not hit the bench as it breaks through. A door on a knee is not clamped. A self-feeding tip will twist the drill if the piece can spin.
You do not need a pilot before a straight centre point. Seat the 1/4 inch hex fully and keep the drill square. Use a side handle once the diameter is around 20 mm or more. That is a rule of thumb, not a standard for these listings. At work, PUWER expects a suitable machine and a trained person. Keep hands out of the plane of the blade. One DeWalt reviewer cut a hand on the bit before any hole. Unplug the drill to change the bit.
Feed, chips, and heat
A plain paddle cuts because you push. Ease off if the drill stalls, and pull the bit out when the chips stop clearing. A spade bit packs the hole, the lip rubs, and the timber burns. There is no rpm chart here for these twelve listings. If the edge smokes in softwood after a few seconds, you are rubbing. Come out, let it cool, and clear the hole.
A threaded tip changes the push. Bosch’s Expert bits pull themselves in, and the bullets limit those rows to softwood and particleboard. Use light pressure, because body weight fights the thread. If the work is loose, the drill rotates the work. The 3× line is only against Bosch bit 2609255269. It is not a speed setting. haierr reviews describe burning and a snap. That is a report about that edge, not a method. WORKPRO reviews say brick contact bent the bits. A wood bit that has met masonry is finished for clean timber.
The exit face
The centre point breaks through first and the exit bursts. Clamp scrap against the back, or stop when the point shows and finish from the other side. On the Expert bits, reverse out before the blades burst the face, because the thread keeps pulling. A hidden stud hole can stay rough. A BULLITT review calls the cut fast but rough. A door face cannot. Little tear-out in a review is not a promise on unsupported ply. If the hole must be flat-bottomed, you want a Forstner bit. Clear the chips once more before the last few millimetres, and withdraw while the drill is still turning.
When to stop
Hammer mode is the hard stop. An impact-rated hex means an impact driver, not masonry mode. One DeWalt reviewer found hairy holes from an impacter and preferred a screw gun. If the bit grabs and then spins free, you have hit metal. Come out.
Gunpla reviews include bent 10 mm points. EZUVITA’s 16 mm bit is described as wobbling. Do not run a blunt bit in to sharpen it. Wear goggles.
If the hole is in a joist, read the joist cable holes page before you centre the point. If the chips pack however often you withdraw, spade bit versus auger is the next decision.
Common questions
Do I need a pilot hole before the spade point?
Not if the centre point is straight. Mark the centre and start square. A bent point, in Gunpla six-piece and WORKPRO reviews, will not locate. Replace the bit. Use the breakthrough pinhole as the centre only when you finish from the reverse side.
How do I stop the back of the board splintering?
Clamp scrap against the exit, or stop when the point appears and finish from the other side. Unsupported ply is how the lips burst the fibres. A hidden stud hole can stay rough. A visible face cannot, and scrap does not make a Forstner finish.
When should I pull the bit out to clear chips?
When the bit stalls, the hole stops throwing chips, or you smell burning. Withdraw while it is still turning, clear the waste, and go back. There is no rpm here to quote. Smoke in the first few seconds is pressure or a blunt edge.
What changes if the tip is threaded?
You stop pushing hard. Bosch’s Expert bits pull themselves in, and those listings are softwood and particleboard only. Clamp the work, because the thread keeps feeding. Reverse out rather than fighting it in forward gear. The 3× line is only against Bosch bit 2609255269.
Can I use hammer mode on a hex shank?
No. A 1/4 inch hex, including an impact-rated Bosch hex or a DeWalt bullet that says impact-ready, is still a rotary wood bit. If an impacter leaves hairy holes, use a drill driver.
What if the bit burns, or was blunt in the reviews?
Stop. Clear the chips and look at the lip. haierr reviews describe blunt, then snap. WORKPRO reviews describe bends after brick. Change the bit. A wobble, as on the EZUVITA 16 mm note, will not leave a round hole. Wear goggles.
Related pages
Sources
Public UK sources last checked on 19 October 2026. Shelf prices, stars and review counts are the amazon.co.uk listings read on that date.
- CMT Group UK, drill bits for construction materials (retrieved 19 October 2026)
- BuildWiz UK, drill bits (retrieved 19 October 2026)
- LABC, notches and holes in solid timber joists (retrieved 19 October 2026)
- East Lindsey Guidance Note 15, notches and holes (retrieved 19 October 2026)
- Professional Electrician, notches and holes in joists (retrieved 19 October 2026)
- HSE CIS65, concealed cables (retrieved 19 October 2026)
- HSE INDG291, PUWER and drilling machines (retrieved 19 October 2026)
- Bosch Professional GB, Expert SelfCut Speed spade bits (retrieved 19 October 2026)