516-127-26 Mitutoyo Rectangle Steel Gage Block Set, 8pc Grade AS-1Mitutoyo Rectangle Steel Gage Block Set (8 blocks per set) All Mitutoyo gage blocks meet or exceed all known specifications. The flatness, parallelism and surface finish necessary to achieve the required accuracies are the same as or better than government requirements. A Certificate of Inspection is furnished with all Mitutoyo gage blocks with a serial number on the case and an identification number on each block. The deviation of each block is