1-2-3 Blocks Matched Pair Hardened Tool Steel Multiple Hole Configurations

123 blocks have an almost endless array of uses in the shop and can be used for machine set up, layout and inspection.  Specifications:  No Hole: Made of hardened tool steel (RC 56-60) Precision ground on all six sides Overall size within +/- 0.0001" (one ten thousandth of an inch)  Flatness and parallelism within +/- 0.0001" (one ten thousandth of an inch)  Squareness on all sides to within +/- 0.0003" per inch (three ten thousandths of an inch)  Pairs are matched to a tolerance of 0.0002" (two ten thousandths of an inch)  Two (2) pieces per set   Approximate weight per block: 786 grams.1.72 pounds One Hole: Made of hardened tool steel (RC 56-60) Precision ground on all six sides Overall size within +/- 0.0001" (one ten thousandth of an inch)  Flatness and parallelism within +/- 0.0001" (one ten thousandth of an inch)  Squareness on all sides to within +/- 0.0003" per inch (three ten thousandths of an inch)  Pairs are matched to a tolerance of 0.0002" (two ten thousandths of an inc