Precision Hardened Steel 1-2-3 Blocks 23 Holes, 1" x 2" x 3"

These precision 1-2-3 blocks are ground and case hardened on all sides to 50-60 Rc. The blocks are 2.5cm by 5cm by 7.5cm. They are parallel within 0.0002", flat within 0.0002" and square within 0.0002". Each set includes two matched blocks. The blocks have 23 holes through them, 5 are threaded 3/8"-16 NC. Quickly set up router bits, table saw, drillpress or any other critical measurement with this high quality steel set up block set.