lag-screw

The Century Dictionary: The Encyelopedic Lexicon of the English Language · 1887 · p. 674

(lag’skré), m. 1. A flat-headed screw, used principally to attach lags to band-drums. —2. Aniron bolt with a square or hexagonal head and cut with a wood-screw thread. It is cylindrical under the bead, so as to admit of turning after it has entered the wood. In Great Britain called coach-screw. Car-Builder’s Dict.