Channel inlet edge deburring for gas diffuser cases

A method of deburring channel inlet edges inside a cavity of a gas diffuser case, the diffuser case having a plurality of channels each having an inner surface and an inlet edge defining an inlet of the channel, the surfaces of adjacent channels co-operating to provide said inlet edge therebetween, the inlet edges of the channels being provided in an inwardly facing circular array around a central axis of the gas diffuser case, the method comprising:

• inserting a tool head having at least one nozzle in an inward position relative to circular array of the channels of the gas diffuser case;
• ejecting abrasive particles from the at least one nozzle from the inward position relative to the circular array, towards at least one of the channel inlet edges of the gas diffuser case and outwardly of the circular array, to deburr at least one said edge;
• and
• without removing the tool head from the inward position relative to the circular array of the channels, causing a relative rotation between the tool head and the circular array of channels to expose at least another of the channel inlet edges of the gas diffuser case to the abrasive particles.