An analysis is presented showing the manner in which an initial point disturbance on the surface of one disk of a pair of radially loaded disks rolling and sliding in contact will grow and propagate other surface disturbances on both disks. In the analysis it is assumed that an area becoming disturbed will be able to cause disturbances on surfaces which come into contact with it. The patterns of the disturbances formed have been compared with scuff patterns on pairs of failed disks, and significant similarities are shown. The number of disturbances and the spacing of the leading edges of the disturbances are similar to the number and spacing of the scuff marks. The analysis gives lengths of the disturbances somewhat longer than the scuff marks. It is concluded that the analysis is helpful in understanding failures on disks, and it can be extended to scuff propagation on gears.Presented as an American Society of Lubrication Engineers paper ASLE/ASME Lubrication Conference held in Chicago, Illinois, October 17–19, 1967.