AbstractThis paper examines the wear characteristics of M50 and T 1 high speed steels at temperatures up to 600°C by means of pin on disc wear tests. The mechanism is found to be one of severe oxidation wear for loads of 10-50 N; wear increasing with load applied. The T 1 steel showed superior wear resistance to M50 but was not wear resistant above 400°C and showed a very high wear rate at 600°C.