Review on 📐 Mitutoyo Steel Rectangular Block Length Calibration Test & Measurement Tool by Jack Ford

These great gauge blocks. I use them to test my mics, calipers and calipers. Only the nominal length is calibrated. Class AS-1 means they are calibrated to plus or minus 0.2 microns. The rule of thumb is to use a gauge block that is 10 times more accurate than the instrument you will be using to check. In this case, the AC-1 brand is enough to check my micrometer with a resolution of 0.002 mm. NIST has a good gage block manual available for download at http://www.nist.gov/caulibrations/upload/mono180.pdf.