AbstractRecent developments in plasma heat treatment equipment and processing techniques are reviewed. This process, which is now firmly established in the UK, is being used in a wide range of applications. Case histories are presented to illustrate some of the associated advantages and potential drawbacks. Temperature uniformity within the vacuum vessel is identified as the major problem when treating mixed workloads. Advances in the field of plasma carburising have led to improvements in the design of nitriding equipment and in particular to the development of pulse power supplies and additional heating systems. Equipment incorporating these features is claimed to give improved temperature uniformity throughout the workload. Plasma carburising equipment is now available and production facilities are operational in the USA, France, Japan, and the FRG. The current status of plasma carburising is assessed, and the areas which present problems are identified.