I would like a second opinion from others on this matter. I just got back a set of gauge blocks fom being calibrated. Two of the blocks were found to be out of tolerance. One block was over the maximun tolerance limit and the other was under the tolerance limit. These blocks are never used during the year. The just lay in the box. My question is how did these blocks go out of tolerance? What phenomenon is taking place to make them go out of tolerance? Or did the calibration company not get good readings? Thanks in advance!