A study was conducted to determine the effect of the number of lobes and lobe height on out-of-round shafts, shaft speed, seal lip load, and fluid temperature on the lip wear characteristics of polyacrylate radial lip seals. Seals molded from four compounds formulated with and without graphite in both plain and helical lip configurations were investigated by means of a fractional factorial experiment. Results of the study show lip load, shaft lobe height, and number of lobes to be significant at the I percent level while shaft speed and fluid temperature are significant at the 5 percent level. The addition of graphite and lip design had no significant effect. An analysis of the results suggests that the seals were operating hydrodynamically.Presented at the 31st Annual Meeting in Philadelphia, Pennsylvania, May 10–13, 1976