Broken bolt extractor for a flush stud or sheared bolt
Updated: 22 October 2026
The head has gone. You are looking at a stud or a bolt broken flush with an engine casing, a hub, a bracket or a machine face, and a spanner has nothing to hold. A broken bolt extractor in that situation means a centred pilot and then a spiral or a left-hand drill, not pliers and not a hex key. The rows are the [screw extractor comparison](/hub/screws-and-accessories/screw-extractor). Peter F. used amazon.co.uk listings, UK review themes and the RS Components UK extractor guide, updated 22 October 2026. There is no lab test and no promise a wheel stud will come out. Amazon.co.uk links may earn a commission at no extra cost to you.
The head has gone. You are looking at a stud or a bolt broken flush with an engine casing, a hub, a bracket or a machine face, and a spanner has nothing to hold.
The head has gone. You are looking at a stud or a bolt broken flush with an engine casing, a hub, a bracket or a machine face, and a spanner has nothing to hold. A broken bolt extractor in that situation means a centred pilot and then a spiral or a left-hand drill, not pliers and not a hex key. The rows are the screw extractor comparison. Peter F. used amazon.co.uk listings, UK review themes and the RS Components UK extractor guide, updated 22 October 2026. There is no lab test and no promise a wheel stud will come out. Amazon.co.uk links may earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Tool type | Size on the listing | Drills in the box | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  BGS BGS 1896 spiral set | Spiral stud extractor | 3–6 mm up to 19–25 mm | No separate drills in the listing | 8.4 | about £5.60 | View offer |
| Alternative |  Bryze Bryze 10-piece left-hand set | Left-hand drills and extractors | Drills 1/8 in to 19/64 in; #1 to #5 | Five #6542 left-hand twist drills | 8.0 | about £13.99 | View offer |
| Alternative |  S&R S&R 5-piece spiral set | Spiral stud extractor | M3 to M18 on the title | No separate drills in the listing | 8.0 | about £13.58 | View offer |
On this page
Flush versus proud
Run a finger or a straight edge across the break. If metal of the head still stands above the surface, you may have a plier job or a double-ended job. The Engineer PZ-58, 4.7 from 9,982 ratings, is for heads of about 3 mm to 9.5 mm. It cannot pull a flush stud. The Engineer DBZ-20 is for a rounded hex of 2 mm to 5 mm that is still proud. A sheared stud has no socket left. A flush break needs a centred pilot before any extractor bites. Double-ended kits disappoint on large shanks because the drill end is small. That proud-head path is the stripped screw extractor page.
Spiral set size bands
Read the band the listing prints. Do not convert #0 to #4 into millimetres. BGS 1896, £5.60, 4.1 from 2,311 ratings, is six carbon-steel spirals from 3–6 mm up to 19–25 mm, with no separate drill. The drive fields say internal hex, but it is a spiral stud set. If your stud is outside every band, the set does not cover it. S&R is £13.58, 4.0 from 1,913 ratings, M3 to M18 on the title, while a head-size field says M6. UK reviews mention wheel nuts that came out, and extractors that snapped. Bryze, £13.99 and 4.1 from 93 ratings, pairs left-hand drills from 1/8 in to 19/64 in with extractors #1 to #5. The best-value label sits on BGS for coverage and price. A snap in a loaded stud is still a snap at £5.60.
Step by step on a flush break
Punch the centre of the broken face. If you cannot mark the middle, do not drill. Drill on that mark, square to the surface, inside the band you intend to use. The RS Components UK guide describes a pilot, then an anti-clockwise spiral with a spanner or a drill in reverse. This page does not invent a pilot diameter. Choose the spiral that matches the hole, not the biggest piece. Tap the flutes, then turn anti-clockwise. If you have Bryze’s left-hand drills, run those anti-clockwise first. If the bolt stays, fit the extractor and stay in reverse. Keep oil off brakes and belts. Do not heat a suspension or hub bolt in the driveway. Stop if the extractor twists, smokes or ovals the hole.
Snap, oval hole, and when a garage takes over
If the extractor breaks in the hole, leave the fragment. A larger bit on a broken spiral walks off centre. Call a professional when the fragment is in an engine, hub or suspension stud, when a wheel stud is off-centre, when the hole is oval, or when a coating may contain asbestos. HSE sheet a27 is that stop. Consumer Rights Act 2015, section 9, judges quality against the description and the price. A £5.60 set that snaps can still have matched its description. It is not a warranty that every stud will move.
Why double-ended kits fail on studs
A double-ended set such as Kuyotine, Ryster or SKmoon is sized for a head still on the surface, often #0 to #4 with drills around 2.0 mm to 3.5 mm. A sheared wheel stud is a larger shank. Those kits can suit a stripped door screw. They are the wrong first tool for a headless stud. Left-hand drills sometimes back the bolt out as they cut. Bryze sells that pair. Hard wheel nuts still snap extractors, and 93 ratings will not tell you the hub is safe. If the first attempt walks on a brake or suspension stud, stop.
Common questions
What size pilot hole for a spiral extractor?
Use the band printed on the set. BGS 1896 runs from 3–6 mm up to 19–25 mm across six pieces. S&R prints M3 to M18 on the title. Neither listing gives one universal pilot diameter, and this guide does not invent one. Drill a hole that matches the extractor you will seat, and stay inside the parent metal of the stud.
What if the extractor breaks inside the hole?
Stop. Do not run a larger extractor down the same hole. A fragment in an engine, hub or suspension stud needs a professional who can drill it out on a machine. A fragment you then ovalise becomes a helicoil or a replacement part, not a second attempt with a cheaper set. Do not leave steel swarf in a brake or bearing.
Left-hand drill or spiral, which first?
If the set includes left-hand drills, use them first, turning anti-clockwise, because they sometimes wind the bolt out as they cut. Bryze is that pair in this comparison. If the bolt does not move, seat the spiral and keep turning anti-clockwise. A spiral without a pilot, or a left-hand drill run clockwise, fights the tool. BGS 1896 has no left-hand drills in the listing, so its path is punch, pilot, then spiral.
Is heat or penetrating fluid safe on suspension?
Penetrating fluid on a rusty thread is a normal step where you can keep it off friction surfaces. Heat on a suspension, hub or brake fastener is not a DIY step this page supports. Those studs are structural, and a snapped extractor there is already on the professional list. If fluid soaks a brake disc or pad, replace the contaminated part rather than hoping it dries. Do not flame a coated fixing that might contain asbestos.
Does BGS size 6 cover my stud?
Only if the shank or the pilot you drilled falls inside the band printed for that piece. The set’s six bands run from 3–6 mm up to 19–25 mm. Size numbers are not a hidden millimetre conversion, and they are not the same as extractor #0 to #4. If the stud is larger than the top band, or smaller than the bottom band, BGS 1896 does not cover it. Measure before you drill the parent metal to match a guess.
Related pages
Sources
UK public sources and the maker page named in the digest for this comparison. Shelf prices, stars and review counts are the amazon.co.uk figures in the stored listings.
- GOV.UK, General Product Safety Regulations 2005: Great Britain (retrieved 22 October 2026)
- The General Product Safety Regulations 2005 (retrieved 22 October 2026)
- Consumer Rights Act 2015, section 9 (retrieved 22 October 2026)
- HSE, PUWER overview (retrieved 22 October 2026)
- HSE, eye protection (retrieved 22 October 2026)
- RS Components UK, screw extractors guide (retrieved 22 October 2026)
- ENGINEER PZ-58 specification (retrieved 22 October 2026)
- GOV.UK, spiral-flute stud removers tool sheet (retrieved 22 October 2026)