It is generally accepted that in order to be described as a powder, a granular
solid should have a particle size below about 1 mm (1000 mm). For powder
metallurgy (PM) uses, we would describe as coarse powders, those with
signifcant proportions above about 150 mm (100 mesh). A good example
of coarse powder would be the powders used in the hot isostatic pressing
(HIP) of shapes and billets. These at one time could range up to 850 mm for
high speed steel (HSS) billet production, but most producers now tend to use