Blocks, 1-2-3, Universal 11 Hole Set 

These 1-2-3 blocks are ground and case hardened on all sides to 55-62 Rc. The blocks are 1" x 2" x 3".

They are parallel within 0.0002" and have a .0001" to .0003" over allowance for nominal lapping.

Each set includes two matched blocks. These blocks can be bolted together using 5/16"-18 socket head cap screws (not included).

The blocks have 11 holes, six drilled through with deep recesses for clamping, and five tapped holes which are threaded 5/16"-18 NC.