A hardened, tapered extractor with a left-hand spiral that bites harder the more it is turned counterclockwise in a pilot hole drilled in the broken fastener. The taper also wedges the stub outward against its own threads, so on a seized bolt the extractor often snaps, leaving a piece of hardened steel that drills cannot touch. Experienced hands try heat, left-hand drill bits and straight-flute extractors first.
Don't reach for the easy-out yet, heat it and try a left-hand drill, snap an extractor in there and it's off to EDM.
Snap an extractor in the hole and the job just got much worse; heat, penetrating oil and patience come first.
Also heard as
- screw extractor
- EZ-out
- bolt extractor
Related terms
Twisted off
Describes a bolt or screw that snapped in torsion while being tightened or removed, leaving the stub behind.
Rounded off
Describes a hex head, nut or socket recess whose corners have worn smooth so wrenches just slip.
Left-hand thread
A thread that tightens counterclockwise, used where normal rotation would loosen a right-hand fastener.