A series of hole drilling tests has been carried out on a range of Hog
anas steel powder compacts, die pressed and sintered to different dens
ities and given a post-sintering impregnation treatment. The tests wer
e designed, first to assess how machinability was affected by varying
drilling conditions and to establish an optimum set for each material,
and second to assess the degree of repeatability and standard of hole
quality, under each set of optimum drilling conditions.