This is a matched set (2 each) of professional quality 2-3-4 blocks They are precision ground and case hardened to RC 55-62 on all six sides. They contain 23 each 3/8 inch through holes (5 tapped with 3/8-16 threads and 18 untapped). Overall size is within +/- .0003″. Flatness and parallelism are within .0003″. Squareness on all sides to within 0.0003″. Pairs are matched to a tolerance of 0.0002″. There are 2 pieces per set.








