Accuracy:Overall size is within +/- .0002; flatness and parallelism on all 6 sides within .0002.
Material: Made of precision-grade tool steel hardened and ground on all 6 sides of block, heat treated and case hardened to HRC 55-62.
Process: It is made of precision tool steel, case hardened and precision ground on all 6 sides of each block,used for set-up, layout and inspection jobs.
Strength: 23 holes include (5) 3/8-16 threaded hole clamping and (18) non-threaded hole. The cross-drilling design allows for effecient use of lower weight with maximum strength.