1793 J. SmeatonNarr. Edystone Lighthouse (ed. 2) §42 (note) Jag or bearded bolts or spikes, are such as with a chissel have a beard raised upon their angles.
extracted from jagn.1
jag-bolt
jag-boltv. to fasten with a jag-bolt.
Π
1793 J. SmeatonNarr. Edystone Lighthouse (ed. 2) §48 The uprights were also jag-bolted and trenailed to one another.