A nib bolt is similar to a cup square (carriage) bolt but includes small serrated nibs under the head instead of a full square neck. These nibs bite into the surface of timber or steel to prevent rotation when the nut is tightened. The domed head provides a clean finish and tamper-resistant fastening, while the nibs allow secure installation even where a square neck would not seat properly.
Common Uses
Timber structures and fencing
Securing metal fittings to wood
Trailer and gate fabrication
General construction where a locking feature is needed without a square neck
