A seized bolt, a rounded head, and a stud snapped off flush are three different problems on one shelf. This is the map: the order the pros work in, where each guide on this site takes over, and the short list worth owning.
Look at the fastener before the shelf. Three cases cover nearly everything.
A seizing problem: chemistry plus patience. The flagship guide scores six independent tests into three picks — Seafoam Deep Creep, Liquid Wrench, and the forum sleeper Free All.
A grip or repair problem; no penetrant fixes either. That guide separates the four failure modes and starts with the undersized six-point socket trick.
The next page in this cluster, unlinked until it is published. Until then: straight-flute, centered hole, heat first.
Every rung hurts less when it fails than the one below it: a wasted soak loses a night, a snapped extractor loses the part to a machine shop.
| Rung | What it does | Move down when |
|---|---|---|
| 1. Penetrant + time | Creeps into the thread gap and lowers breakaway torque. Every product in Project Farm's finale worked better at 24 hours than at one. | An overnight soak has not moved it. |
| 2. Heat | Expands the casting and cracks the rust bond; a torch beat every oil in Project Farm's first test (91.5 ft-lbs vs the winning can's 97.3). Never take it to red — a 2016 Garage Journal thread warns that hardens the bolt for later drilling. | Three cycles do nothing, or fuel, rubber, or aluminum is in range. |
| 3. Shock | A hand impact driver turns a hammer blow into a hard twist while forcing the bit into the recess; Lisle rates its 29200 at over 200 ft-lbs of shock torque. | The head or recess is rounding under it. |
| 4. Fresh grip | A six-point socket one size down, hammered on; bolt-extractor sockets or locking pliers on anything proud. The stripped-bolt guide owns this rung. | There is no head left. |
| 5. Left-hand drill bit | Drilling in reverse makes the cutting direction the loosening direction; a 2010 Garage Journal thread reports the stub often spins out before the hole is done. | The hole is drilled and the stub will not turn. |
| 6. Extractor | Straight-flute or spline only, in a centered hole, on a bolt that broke from over-torque rather than rust. Doctrine below. | It slips or starts to wind up. Stop before it snaps. |
| 7. Drill it out | Step up bit sizes to just under the minor diameter, chase the threads with a tap, thread insert if they fail — the fallback in the 2020 Garage Journal thread. | The hole wandered; that is thread repair now. |
| 8. Weld a nut on | Heat exactly where the rust is, a new full-size head, and a stub that shrinks as it cools. Method per a 2023 thread: washer first on a flush stub, fill the nut's bore, work it back and forth, repeat if it fights. | No welder, or the stub sits in an aluminum head. |
The clearest statement is a July 2020 Garage Journal thread. The answers discuss type before brand: several posters warn that long round spiral easy-outs expand the bolt, and one calls buying them practice for removing broken extractors. The preference runs to straight-flute and spline tools — Lisle's spline set, Irwin's multi-spline, Proto's tapered squares, Snap-on's SR40K — plus the one prerequisite no tool fixes: a square, centered hole.
A 2010 thread on the same forum says the same a decade earlier: spirals overgrip, straight flutes win, Snap-on's multi-spline first. The counterweight from the stripped-bolt guide: an extractor is built for a bolt that snapped from over-torque, not rust. This page picks no set; that is the next page, unlinked until it exists.
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The flagship guide's best-overall pick: won Project Farm's toughest single round and held up across his series. Researched only.
For: the first can on any seized bolt
Skip if: you already own a can that works
Check price on AmazonFive sizes, 5/64 to 19/64 inch, M-42 cobalt, 135-degree split point; Irwin's own page pairs them with extractors. Researched only.
For: any bolt snapped off flush
Skip if: you only fight rounded heads — a socket problem
Check price on Amazon3/8-inch drive, 5–50 ft-lb, 72-tooth dual-direction head, stated ±3 percent accuracy, per etoolab's listing. Owned and used; not put on a tester, so those are the maker's numbers.
For: putting the bolt back to spec, not to feel
Skip if: your fasteners live above 50 ft-lb — a 1/2-inch-drive job
Check price on AmazonLiquid Wrench and Free All are the flagship's other two winners. The Lisle 29200 hand impact set is the shock rung: owners in a 2014 Garage Journal thread say the US-made driver freed rotor and motorcycle case screws for years; the included Phillips bits are the weak point.
Unlinked on purpose: bolt-extractor sockets, locking pliers, induction heaters, every extractor set. No verified product yet, no button.
Chase the hole with a tap and wire-brush the bolt; the Permatex anti-seize data sheet makes clean, dry surfaces the first step, and a torque reading on a dirty thread is a reading of the dirt. I use the etoolab 3/8-inch click wrench above, wound back to its lowest setting between jobs.
Anti-seize is for fasteners that must come apart later out of heat or corrosion. Permatex's aluminum-copper-graphite Anti-Seize Lubricant is rated from -60°F to 1,600°F, listed for spark plugs in aluminum heads, exhaust bolts, and U-bolts, and carries one warning in capitals: not for wheel lug nuts or studs.
Threadlocker is for fasteners that must not vibrate loose. Loctite 242, the blue one on my shelf, is rated by Henkel's data sheet for 1/4- to 3/4-inch fasteners, sets in about ten minutes, cures in 24 hours, and releases with hand tools. Both live on the workshop consumables page.
Now the conflict. Permatex says reassemble at normal torque values. Fastenal's chart computes torque as T = KDF with K = 0.20 for dry threads and 0.15 for lubricated — the same number on a lubricated thread gives roughly a third more clamp load, enough to pass yield. They disagree and I will not pretend otherwise. My rule: follow the service manual and its stated condition; if it assumes dry and you added anti-seize, back the number down or skip the anti-seize.
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