Used in layout and setup work. Each set consists of 2 matched, hardened and precision-ground blocks. The squareness on all sides is within .0001" per inch. The blocks are supplied with a plus allowance of .0001" to .0003" to allow nominal lapping. Five 3/8"-16 tapped holes are provided for clamping. 5 stainless steel socket head 3/8" - 16 cap screws, one hex key in a plastic fitted case.
