V block

noun

1. a block having a precise V -shaped groove for checking the roundness or concentricity of a machine part or the like, or for holding cylindrical pieces of work.

Example Sentences

By thus welding one side at a time the welding is taken in detail as it were, and the blows can be less heavy than if a larger weld were made at one heat, as would be the case if but one V block were used.

From Project Gutenberg

In jargon, used very similarly to v. block; also in `sleep on', syn. with `block on'.

From Project Gutenberg