Conventional machining of compacted ceramic preforms can be a cost-effective method of making small production runs of complex-shaped engineering ceramics. This paper discusses the factors influencing chipping resistance and edge retention for two spray-dried zirconia powders. The chipping resistance did not deteriorate significantly, neither did the swarf size change after pre-sintering the components at temperatures up to 1000°C despite a twenty-fold increase in compact strength. It is argued that machinability is only indirectly dependent on compact strength but is dependent directly on the initial defect size and cutting parameters.