411 REFERENCE · Wiktionary
2-4-6 block
Reference material by Wiktionary contributors. This retains its source identity and is not 411 news reporting.
English
Noun
2-4-6 block
A tool used in machining fields, especially milling, to aid in setup. It is a block of steel that is precisely squared and parallel whose sides are 2, 4, and 6 inches long, respectively. 2-4-6 blocks are a larger version of the more common 1-2-3 block.