Wringing gage blocks is the process of assembling gage blocks together end-to-end to achieve a specific measurement. Not everyone uses gage blocks in wrung combinations, but wringability can provide a test of the integrity of the surface condition of the gage block. Gage blocks that do not wring may give erratic and unreliable results. In fact, gage block specifications recommend replacing blocks that have lost their ability to wring.
Gage block length is defined as an interferometric measurement when the gage block is wrung to a flat platen. Gage block wring is incorporated into the lengths of the blocks themselves, and wringing film is included in the defined length of the gage block. When gage blocks are assembled in combinations, no additional correction factor for wringing films needs to be added to the length of the combination.