The Lockformer® Skip Dent Indexing Roll is the heart of the system. The indexer is the first roll and has four pins and two milled ridges. The control lever determines whether the blank is hemmed after the first or second notch. With the lever in position 1, as the blank engages the indexing roll, a pin drops into the fi rst notch. A ridge adjacent to the pin prebends the material at its corner just enough to force the material into the hem forming rolls where the 180 degree hem is formed. The next pin, on the rotating index roll, drops into the second notch and since there is no ridge present, the corner of the blank is not turned down and misses the hemming rolls and this section remains unformed.