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Self-centring drill bit for door hinges

Updated: 23 October 2026

You are hanging a butt hinge on a timber door. The screw has to land in the middle of the countersink or the head sits proud. A self-centring drill bit uses the leaf as the jig and starts a short pilot. It does not mortise the hinge or bore a 35 mm cup. Which box to buy is the [best hinge drill bit](/hub/drilling-and-accessories/hinge-drill-bit/sub/hinge-drill-bit-best) page. Listings are on the [hinge drill bit comparison](/hub/drilling-and-accessories/hinge-drill-bit). Checked on 21 October 2026. There is no lab test. A qualifying purchase through our links can earn a commission at no extra cost to you.

You are hanging a butt hinge on a timber door. The screw has to land in the middle of the countersink or the head sits proud. A self-centring drill bit uses the leaf as the jig and starts a short pilot.

Our top picks

Trend Trend QR/DBG/SET 3-piece guide

Best overall

Trend Trend QR/DBG/SET 3-piece guide
9.0/10about £15.95
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Ancable Ancable 2.4 / 2.8 / 3.6 mm set

Best value

Ancable Ancable 2.4 / 2.8 / 3.6 mm set
8.5/10about £9.99
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KAHEIGN KAHEIGN self-centring set

Rank 3

KAHEIGN KAHEIGN self-centring set
7.3/10about £9.99
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On this page
  1. 1.The leaf is the template
  2. 2.Size follows the screw, not the hinge length
  3. 3.A short hole can still be the right start
  4. 4.Fire doors and the wrong tool

The leaf is the template

Eye-drilling a hinge screw is how the head finishes on one side of the countersink. The hole in the leaf is already round. A self-centring guide puts a sprung nose in that countersink and drills on the same centre. The bit does not know where a 3 inch butt should sit. The nose fails when the bit is too big. A KAHEIGN review says the smaller bits can centre and the larger sizes will not seat in a standard internal-door hinge hole. If the sleeve will not enter the countersink, that size is wrong for that leaf. Drill with the leaf held where it will live, then drive one screw before the rest.

Size follows the screw, not the hinge length

A 4 inch hinge is not a bit size, and nor is a 3 inch hinge. The pilot follows the screw. diydata.com lists a No.8 softwood pilot of 2.0 mm and a hardwood pilot of 2.4 mm. squote.app puts hardwood near 2.8 mm. woodcalcs.uk lists 2.5 mm and 3.0 mm. You are not drilling the clearance. The leaf has that. Trend Snappy is 2 mm, 2.75 mm and 3.5 mm for No.6, No.8 and No.10. QR/DBG/SET prints 2.4 mm, 2.8 mm and 3.6 mm. If the packet says No.8, use the guide that maker labelled No.8 and test it in scrap. A neighbouring size is enough. Fractions up to 1/4 inch are not.
Trend Trend QR/DBG/SET 3-piece guide

Testsieger

Trend Trend QR/DBG/SET 3-piece guide
9.0/10about £15.95
View offer

A short hole can still be the right start

The sleeve will not drill the full length of a hinge screw. Trend reviews say the pilot stops early. FAMAG lists about 9 mm and 10 mm on its smaller guides. Finish with a normal bit of the same diameter. Forcing a 30 mm screw into a short pilot is how the head stays proud and the edge splits. Oak dust jams the windows. Clear them before the sleeve stops returning. Ancable reviews add bits that are not size-marked, so mark them if the steel is blank. Drive the first screw by hand and stop when the head meets the countersink. A further half-turn pulls the leaf in.

Fire doors and the wrong tool

An ordinary internal door is the job this bit is for. A certificated fire door is not. The DHF and GAI code points timber fire-door hinges to EN 1935 and to screws not smaller than No.8 and not shorter than 30 mm, unless the certificate says otherwise. Do not reach for a 35 mm cup bit because it also says hinge. The mortise is a chisel or a router job before any pilot. If the door is rated, use a fire-door fitter. Cup depth is on the 35 mm hinge drill bit page.

Common questions

Will this centre the screws on a butt hinge?
Yes, if the nose seats fully in the countersink and you start the drill only after that. The leaf is the template. The bit does not position the hinge on the door. If the nose is too large to enter the hole, that size will not centre anything.
What size bit for a normal internal-door hinge?
The size of the screw, not the length of the hinge. No.8 is a common timber fire-door minimum in the DHF and GAI code, but the pilot in millimetres is not one British Standard. Trend’s two kits print different No.8 pilots, 2.75 mm and 2.8 mm. Match the column, then test one hole.
Why do the screw heads still sit proud?
Usually the pilot is too shallow, or off centre so the head rests on one rim. Trend reviews describe sleeves that stop early. Finish with a twist bit of the same diameter before you drive the screw. If the head is still proud, the countersink in the hinge is the stop.
The sleeve only goes in a little. Is it broken?
Often it is working as designed. Effective lengths around 9 mm to 10 mm appear on FAMAG’s guides, and Trend reviews describe the same short travel. Use the short hole as the centre, then drill on with an ordinary bit. It is broken if the sleeve will not return.
Can I drill a fire door with it?
Not as a DIY repair to a certificated door. Hinges on that door are part of the fire resistance. The code expects EN 1935 hardware and, on timber doors, screws at least No.8 and 30 mm unless the certificate says otherwise. Call a fitter.
Oak dust jams the sleeve. What then?
Stop and clear the side windows before the spring seizes. Oak packs the gaps faster than softwood. Once the sleeve slides again, finish the depth with a clean twist bit. If the spring has collapsed, that guide is finished.
Is a 35 mm bit any use here?
No. A 35 mm bit cuts the cup for a concealed cabinet hinge. A butt hinge needs a shallow mortise the thickness of the leaf, then small pilots for the screws.

Related pages

How to use a hinge drill bit

Hinge drill bit buying guide

Hinge drill bit

35 mm hinge drill bit: cup depth and edge distance

Best hinge drill bit for labelled No.6 to No.10 pilots

Sources

Public sources from the research digest, last checked on 21 October 2026. Shelf prices and star lines are the amazon.co.uk figures in the display file.

  1. Trend Snappy drill bit guides (retrieved 21 October 2026)
  2. Axminster professional hinge drills (retrieved 21 October 2026)
  3. Hart Wholesale, Blum CLIP top BLUMOTION 71B3550 (retrieved 21 October 2026)
  4. Hettich Sensys 110° hinge (retrieved 21 October 2026)
  5. DHF and GAI code of practice, hardware for fire and escape doors (retrieved 21 October 2026)
  6. BWF Fire Door Alliance, fire door hardware (retrieved 21 October 2026)
  7. HSE, PUWER overview (retrieved 21 October 2026)
  8. Consumer Rights Act 2015, section 9 (retrieved 21 October 2026)