These precision 1-2-3 blocks are precision ground and case hardened on all sides to 50-60 Rc.
Each set includes two matched blocks. The blocks are 1" by 2" by 3". They are parallel within 0.0002", flat within 0.0002" and square within 0.0002".
The blocks have 23 holes through them, 5 are threaded 3/8"-16 NC, and the other through holes ar