AbstractA wide scatter was obtained for measurements of wear rate and friction coefficients in sliding wear tests on 95 and 99·5 wt-% alumina using pin-on-disc or pin-on-ring test geometry. Contributions to scatter in wear test data arising from the effect of the material originated in the operation of different wear mechanisms at high and low wear rates and from a velocity dependence of wear properties in the 95% alumina. Consideration of possible effects on variability resulting from changing the test geometry did not identify any specific sources, but there were probably contributions from differences in the vibrational characteristics of the test rigs and from differences in the role played by wear debris in the two types of test geometry.MST/865