How to Use a Screw Extractor Without Breaking It

October 8, 2026

To use a screw extractor, cut a clean seat in the damaged screw, then run the extractor counterclockwise at very low speed with firm pressure so it bites and backs the screw out. Extractors are hardened steel, so they snap if you rush them, tilt them or put them on an impact driver. This guide covers the exact steps, how to size the extractor, how to avoid breaking it, and what to do if one breaks anyway.

What you need

A screw extractor set, such as the 6-piece damaged screw extractor set (six double-ended bits, sizes #0 to #4)
A drill with reverse and variable speed. A cordless drill with a low gear is ideal. Not an impact driver.
Penetrating oil and a little cutting oil
A center punch and hammer
Safety glasses
For snapped bolts: drill bits for the pilot hole, ideally left-handed ones

If the screw is only lightly stripped, try the gentler fixes in how to remove a stripped screw first. An extractor is the step after those.

Know which type of extractor you have

The steps depend on the design, so check before you start.

Double-ended extractors have a cutting end and an extracting end on one bit. You don't drill a separate pilot hole: the cutting end makes the seat, then you flip the bit. They're built for screws with damaged heads. The JUSMIR set is this type.
Spiral (tapered) extractors have a coarse left-hand thread. You drill a pilot hole into the fastener, then turn the extractor in counterclockwise until it grips. They're the usual choice for bolts that have snapped off.
Straight-flute extractors are tapped into a pilot hole and turned with a wrench. They wedge the bolt outward less than spiral types.

All three are hardened so they can bite into a steel fastener. The catch is that hardened steel doesn't bend before it fails. It snaps, and the broken piece is harder than ordinary drill bits.

How to use a double-ended screw extractor

Prepare the screw

Spray penetrating oil around the screw head and let it soak for at least 15 minutes, longer on rusty parts.
Clean paint, dirt and loose metal out of the recess with a pick.
Pick the size. The cutting end should sit inside the damaged recess without reaching the outer edge of the head. In the JUSMIR set, #0 is the smallest and #4 the largest. If two sizes fit, use the larger one: a thicker bit is a stronger bit.

Cut the seat

Fit the cutting end in the drill chuck and tighten it well. Set the drill to reverse and low gear.
Put a drop of cutting oil on the head.
Hold the drill in line with the screw. Check from the side and from above, because any tilt puts a bending load on the bit.
Press firmly and run the drill slowly. Cut a shallow seat, roughly 1.5 to 3 mm (1/16 to 1/8 in) deep, with clean, bright metal all around.

Extract the screw

Careful, the bit may be hot. Flip it so the extractor end faces out, and keep the drill in reverse.
Seat the extractor end in the fresh cut and push hard, harder than feels natural.
Squeeze the trigger gently. Very low speed lets the extractor bite instead of skating. Once it grips, the screw starts to turn.
Keep the speed slow and even until the screw is out.

If the extractor spins in the seat without gripping, stop. Recut the seat a little deeper, or move up one size. Running faster only polishes the seat smooth.

Using an extractor on a broken bolt

A bolt that has snapped off in its hole has no head to work with, so you need a pilot hole and, usually, a spiral extractor sized for that bolt.

File or grind the broken face flat if it's jagged.
Center punch the exact middle. An off-center hole will cut into the threads of the hole when you drill.
Drill the pilot hole in the size stated on the extractor or its packaging. Start with a small bit and step up, keeping the drill straight.
Drill deep enough for the extractor to grip fully, but not so deep that it bottoms out.
If you drill with a left-handed bit in reverse, watch closely: it often catches and spins the bolt out on its own.
Tap the extractor lightly into the hole and turn it counterclockwise by hand with a tap wrench. Turning by hand lets you feel when it's close to its limit.

Be realistic here. The double-ended JUSMIR set is made for damaged screw heads, not for drilling deep into snapped bolts. And a bolt that broke under heavy torque will fight the extractor just as hard, which is why oil, heat and patience matter more than the extractor itself.

How not to snap a screw extractor

No impact drivers. The hammering action shocks a hard, brittle bit. Use a regular drill or turn it by hand.
Stay in line. Side load is the biggest killer. Keep the drill square to the screw and hold it with both hands.
Go slow. Low speed gives the extractor time to bite and gives you time to feel what's happening.
Use the largest size that fits. Small extractors have very little steel in their core.
Loosen the threads first. Penetrating oil, time and a few sharp hammer taps on the screw do more than extra force. If you use heat, wipe off the oil first (it's flammable) and keep flames away from fuel lines, wiring, plastic and rubber.
Know when to stop. If firm, steady pressure doesn't turn it, more force will most likely snap the extractor. Go back to oil and heat, or get help.
Remember the wedge. A tapered extractor pushes outward as it goes in, pressing the bolt harder against its threads. Driving a spiral extractor in harder doesn't always mean more grip.

What to do if the extractor breaks

Stop drilling. An ordinary drill bit won't cut a hardened extractor. It only blunts the bit and polishes the broken face.
Grab anything that sticks out. If part of the extractor stands proud, grip it with locking pliers and turn it gently counterclockwise.
Try to break it up. Hardened steel is brittle, so a sharp punch struck firmly can sometimes crack the broken piece into fragments you can pick out. Wear safety glasses.
Grind it out. A carbide burr or a diamond burr in a rotary tool can grind a hardened piece away. Work slowly and expect it to take time and more than one burr.
Use a machine shop. Shops with EDM (spark erosion) equipment remove broken extractors and taps without touching the surrounding threads. For an engine block or cylinder head, this is often the cheapest route overall.
Repair the hole. If the threads are damaged, a thread repair insert kit restores the original size.

When to call a pro

If the screw or bolt is in an engine block, cylinder head, exhaust manifold or a brake part, and your first careful attempt doesn't work, stop there. A snapped extractor in an expensive part costs far more to fix than paying a shop to remove the original fastener.

If what you're dealing with is a hex bolt head that has rounded, rather than a screw recess or a snapped bolt, an extractor socket is usually the better tool. See how to use a bolt extractor socket set.

FAQ

Do you drill clockwise or counterclockwise with a screw extractor?

With a double-ended extractor, both steps are done in reverse (counterclockwise). With spiral extractors, you drill the pilot hole forward with a normal bit, or in reverse with a left-handed bit, and the extractor itself always turns counterclockwise.

What drill speed should I use?

The lowest your drill allows, with low gear selected. Speed strips the seat and gives you no warning before a bit breaks.

Can I use a screw extractor with an impact driver?

No. The impacts shock the hardened bit and can shatter it. Use a regular drill, or turn it by hand.

Can a screw extractor remove a broken bolt?

Often, if the bolt isn't badly seized and the pilot hole is accurately centered. A bolt that snapped because it was rusted solid may need heat or a machine shop.