1-2-3 block

A 1 times 2 times 3 inch steel block commonly used as a square reference or mount point when milling

English

Noun

1-2-3 block (plural 1-2-3 blocks)

1. 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 1, 2, and 3 inches long, respectively. May contain arranged holes. Similar, larger blocks are called 2-4-6 blocks.

   Synonyms: setup block, machinist block