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rag bolt[′rag ‚bōlt]
barb bolt, rag bolt
A bolt having jagged edges to prevent its being withdrawn from the object into which it is driven.
1. A bolt with a wedge-shaped end inserted like the shank of a lewis in a hole drilled in a stone and fastened therein by pouring melted lead or concrete into the unfilled part of the hole.
2. An eyebolt similarly inserted and used like a lewis for lifting heavy stones.