"Fig. 2. Effect of cup inclination on wear-pattern (angle-A) and margin-of-safety (MOS), A) at 55 ° inclination the cup wear-pattern has a 58° arc and MOS has a 6° arc, B) adding 6°  additional inclination reduces MOS to zero, and C) adding another 9° inclination reduces the cup wear-pattern to a 50° arc and edge wear presents. This edge-wear definition would be EW = 9/58 = 16%""."
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