coach screw

English

Noun

coach screw (plural coach screws)

1. (hardware) A large metal wood screw with a hexagonal head.

   Synonym: lag screw

   • 1943 September and October, “Railway Construction and Operation at War Department Depots”, in Railway Magazine, page 263:

     In turnouts the special fittings are secured by coach screws. Portable air compressors with special tools for boring holes and driving the coach screws save both time and labour.