Countersink bit for wood
Updated: 23 October 2026
You are screwing into pine, oak, plywood or MDF, and the last hole near the edge split. A countersink bit for wood only helps if the pilot is smaller than the shank and the cone matches the head. A plug cutter in the same box is a second tool, and it only hides the screw if the plug is the same diameter as the hole you cut. Prices and review counts for every listing are on the [countersink comparison](/hub/drilling-and-accessories/countersink). The Products Compared editorial team used amazon.co.uk listings and public UK and European fixing notes, as of 20 October 2026. Percentages below are rules of thumb, not a British Standard. There is no lab test. A qualifying purchase can earn a commission at no extra cost to you. Wear eye protection. Wood dust from MDF is a workplace COSHH matter if you are employed to cut it; at home, still clear the dust rather than blow it into the room.
You are screwing into pine, oak, plywood or MDF, and the last hole near the edge split. A countersink bit for wood only helps if the pilot is smaller than the shank and the cone matches the head.
You are screwing into pine, oak, plywood or MDF, and the last hole near the edge split. A countersink bit for wood only helps if the pilot is smaller than the shank and the cone matches the head. A plug cutter in the same box is a second tool, and it only hides the screw if the plug is the same diameter as the hole you cut. Prices and review counts for every listing are on the countersink comparison. The Products Compared editorial team used amazon.co.uk listings and public UK and European fixing notes, as of 20 October 2026. Percentages below are rules of thumb, not a British Standard. There is no lab test. A qualifying purchase can earn a commission at no extra cost to you. Wear eye protection. Wood dust from MDF is a workplace COSHH matter if you are employed to cut it; at home, still clear the dust rather than blow it into the room.
Our top picks
| Badge | Product | Best used in | Pilot | Watch for | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Makita Makita D-73455 4-piece set | Short wood screws | Stated 3–6 mm, often smaller | Tips snap in 4 mm ply | 9.0 | about £7.92 | View offer |
| Alternative |  Gasea Gasea 3-piece 90° countersink | Ply, oak, MDF after a pilot | None — drill it yourself | Softwood looks untidy if slow | 8.8 | about £4.99 | View offer |
 EZARC EZARC 12-piece countersink set | Wood screws, No. 4–12 | 2–3.6 mm, spares in the box | Blunts after about 40 chipboard holes | 8.6 | about £17.99 | View offer |
On this page
Why the screw splits the wood
A wood screw moves fibres aside as it goes in. Near an edge or a knot there is nowhere for those fibres to go, so the face opens. The cone on a countersink does not prevent that. It only makes room for the head. The pilot is what reduces the wedge. If you countersink a hole that is already too tight, you still split the rail, and you now have a neat cone on a crack. WoodCalcs, a UK calculator rather than a standard, uses a rule of thumb: a softwood pilot about 60% of the shank, hardwood about 75%, plywood about 70%, MDF about 80%, and a little larger again near an edge. Enlarge means closer to the shank diameter, not a clearance hole so loose the thread does not bite. A combination bit is already trying to be that undersize pilot. A Makita reviewer in this comparison measured about 4 mm from the size marked 6 mm. That is the right kind of result for a wood screw cutting its thread, and the wrong result if you thought the marking was a clearance drill. The top piece of two boards is a different hole from the bottom piece. The top often wants clearance so the boards pull together, and the bottom wants a pilot so the thread grips. A single combination pass through both pieces gives you the same small hole in each. That is fine for a hinge leaf into one door. It is a poor joint when you are clamping a rail to a stile and you needed the screw to pull. Drill those as two operations, then chamfer only the face you will see.
Softwood, hardwood, plywood and MDF
Pine and other softwoods forgive a slightly tight pilot more than oak or beech do, until you are close to the end grain. The WoodCalcs hardwood figure, about 75% of the shank, is the one to try first in oak, then open it a touch if the screw squeals or the driver cams out. The Timber Decking and Cladding Association uses about 70% of the shank as a hardwood pilot for cladding. The same note says cladding fixings should finish flush and should not be punched or countersunk, because that can split and stain. That is a cladding rule. It is not a ban on countersinking a cabinet door. Sheet materials split less like a board and more like a layer. Plywood can lift a veneer if the cone enters too fast. MDF can erupt at the face if the screw is driven with no relief under the head. The European Panel Federation’s MDF note asks for a pilot about 85–95% of the screw core, at least 1 mm deeper than the screw, face screws at least 12 mm from the edge and 25 mm from corners, and edge screws at least 70 mm from corners. It also wants a small counterbore so the surface does not lift. That counterbore is a shallow seat, not a 19 mm crater. A 12 mm chamfer stopped as soon as the head is flush is in the right family. Gasea reviews include a clean chamfer in marine plywood and in oak, and use in MDF and ply, with softwood looking untidy unless the speed is high. LIBRATON reviews include 18 mm plywood that behaved with light pressure and cleared flutes, and fine pilots that snapped in 18 mm MFC when the bit got hot. Melamine-faced chipboard is abrasive.
Combination bits versus a chamfer you already drilled
The wood combination sets in this comparison are Makita at £7.92, the EZARC 12-piece set at £17.99, TMBMLPP at £9.19, Fentar at £11.99, NORTOOLS at £26.99, LIBRATON at £29.99 and the EZARC 25-piece kit at £31.97. Their surface lines say wood, or short wood screws, or wood with MDF and particle board. They are the tools that drill the pilot with the cone. EZARC’s pilots run from 2 mm on No. 4 to 3.6 mm on No. 12. Makita states 3 mm to 6 mm from No. 6 to No. 12. TMBMLPP states 2.8 mm to 4.0 mm and has only eight reviews, so treat the range as the listing, not as a proven life in oak. A chamfer you have already drilled is Gasea at £4.99, Torveen at £4.19 or YXIING at £6.39, all in 12, 16 and 19 mm, with no pilot. Use one of those when the twist drill has done the hole and you only need the head to sit down. Gasea is the one with 1,122 reviews and a stated 90°. YXIING does not state an angle. ColumPRO and ATOPLEE are not the wood picks here: ColumPRO has no reviews, and ATOPLEE forbids hand drills and limits the steel to softer stock. Match the pilot to the screw in your hand, not to the biggest number on the case. A No. 8 is not an 8 mm hole. If you are within 12 mm of the edge of an MDF panel, move the screw before you buy a sharper bit. The scrap test, once the size is chosen, is on how to use a countersink bit.
Hiding the head with a plug
A plug is a disc cut from matching timber and glued into a counterbore. The cutter that makes the plug has to match the cutter that makes the hole. Axminster’s matching plug sets say the plugs come from an offcut, and that plug cutters belong in a pillar drill only. That holding rule is the one to keep even though that set is not an ASIN here. A pistol drill wanders, the plug becomes oval, and the grain will not sit. LIBRATON includes 3/8 inch and 1/2 inch plug cutters and says they are best on a bench drill. A non-UK review said the plug did not match an 8 mm dowel. Fentar includes eight plug cutters at £11.99 and a review says a 6 mm dowel cutter made 4 mm dowels. Another says the plug cutters were blunt and would not cut pine. Do not assume a Fentar plug will fill a Fentar countersink until you have cut one pair on scrap and they fit. NORTOOLS and the EZARC 25-piece kit also put plug cutters in the case. NORTOOLS has nine reviews. The 25-piece kit’s long texts are not UK reviews. A visible screw is better than a plug that is 2 mm small and a hole full of glue. Cut the plug from an offcut of the same board so the grain is close, glue it, let it dry, and trim it flush. If you only cut a shallow cone for a screw head, there is no pocket for a plug. That is a different setting on a combination bit, or a separate counterbore, not the same depth you used for a flush screw.
Common questions
Do I need a pilot in softwood?
You need one as soon as you are near an edge, in end grain, or using a screw thick enough to wedge the fibres. A rule of thumb from WoodCalcs is about 60% of the shank in softwood. In the middle of a wide pine board a thin screw sometimes goes in without a pilot. That is not a reason to skip the pilot on a 40 mm rail. The countersink still only seats the head.
What changes for oak or beech?
Try a larger pilot, about 70% to 75% of the shank, and expect more heat on the bit. The TDCA figure for hardwood cladding is about 70%. Combination pilots that feel fine in pine can squeal or snap in oak if they are the very fine No. 4 and No. 6 sizes. If the driver cams out, stop and open the pilot slightly rather than leaning on the screw.
How close to the edge can I screw?
On MDF, the European Panel Federation suggests face screws at least 12 mm from the edge and 25 mm from a corner, and edge screws at least 70 mm from a corner. Those are fixing distances, not a guarantee. Solid timber splits on end grain even further in if there is no pilot. If the screw has to sit closer than that, the joint needs a different fixing, not a sharper countersink.
Will a combination bit stop plywood splitting?
It reduces the wedge if the pilot suits the screw, and it can still lift a veneer if you enter too fast or go too deep. LIBRATON reviews include 18 mm plywood that worked with light pressure and cleared flutes. Use the scrap face of the same sheet. A 19 mm chamfer left running will show through a thin veneer long before it helps the screw.
Can I plug the hole with the cutters in the box?
Only after a scrap plug matches the hole. Fentar reviews include a 6 mm cutter that made 4 mm plugs, so the printed size is not enough. LIBRATON tells you to use a bench drill for its plug cutters. Axminster’s own plug-set page says the same about pillar drills. If the plug is loose or oval, leave the screw visible or buy a matched pair and cut them on a drill press.
Is MDF the same pilot as pine?
No. MDF wants a pilot closer to the core of the screw, about 80% on the WoodCalcs rule of thumb and about 85–95% of the core in the European Panel Federation note, and the hole should run at least 1 mm deeper than the screw. Pine can live with a smaller pilot in the middle of a board. MDF also needs the edge distances above. A small counterbore stops the face lifting. A deep 19 mm cone does not.
Which of these sets are actually for wood rather than metal?
Makita, both EZARC kits, LIBRATON, NORTOOLS, Fentar and TMBMLPP are the wood combination listings. Gasea, Torveen and YXIING are chamfers used in wood and also named for aluminium or soft metal, with no pilot. ATOPLEE is a machine cutter with a hardness limit, and the listing bans hand drills. ColumPRO claims metal, including stainless, and has no reviews in this comparison. For a cordless drill in timber, stay with the wood combination sets or a plain chamfer after you have drilled the pilot.
Related pages
Sources
Public UK sources from the research digest, last checked on 22 October 2026. Shelf prices and star lines are the amazon.co.uk figures in the display file.
- HSE PUWER overview (retrieved 22 October 2026)
- HSE L114, Safe use of woodworking machinery (retrieved 22 October 2026)
- HSE WIS23, Wood dust (retrieved 22 October 2026)
- HSE EH44, Dust and eye protection (retrieved 22 October 2026)
- Consumer Rights Act 2015, section 22 (retrieved 22 October 2026)
- Fastenerdata: screw heads (retrieved 22 October 2026)
- ISO 10642:2026 (retrieved 22 October 2026)
- BSI: BS EN ISO 10642:2019 (retrieved 22 October 2026)