The first movement of a fastener being removed, when static friction, corrosion, threadlocker or thread damage must be overcome. Once a nut breaks loose the running torque usually drops sharply. Heat, penetrating oil, an impact wrench, a six-point socket and a steady pull all help; a sudden jerk on a long bar is how studs twist off.
Hit it with heat and let it cool a minute, then break it loose with the six-point, not that twelve-point.
Also heard as
- crack loose
- bust loose
- break it free
Related terms
Breakaway torque
The torque needed to start a tightened fastener turning again, used to audit joints and rate locking features.
Twisted off
Describes a bolt or screw that snapped in torsion while being tightened or removed, leaving the stub behind.
Rattle gun
Shop nickname for an impact wrench, from the hammering racket it makes running fasteners on and off.
Rounded off
Describes a hex head, nut or socket recess whose corners have worn smooth so wrenches just slip.