A two-piece fastener in which a pin with annular grooves passes through the joint and a hydraulic or pneumatic tool swages a metal collar into the grooves while pulling the pin to tension. On breaking types the pintail snaps off at a set load, so preload is consistent and does not depend on torque or friction. Lockbolts are standard on truck frames, trailers, rail cars and solar trackers, and removal means cutting or splitting the collar.
The crossmember is all Huck bolts, so bring the collar cutter, there's no wrench that's getting those off.
Also heard as
- lockbolt
- Huck
- swage bolt
Related terms
Self-loosening
A tightened nut or bolt turning loose by itself, usually because sideways slip in the joint lets it walk off.
Preload
The tension created in a bolt by tightening it, which clamps the joint and keeps it from slipping or opening.
Pop rivet
Shop name for a blind rivet: a hollow rivet set from one side by pulling a mandrel that snaps off when tight.
TC bolt
Tension control bolt: a structural bolt with a splined tip that shears off once the right tension is reached.