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 . For powder metallurgy uses, we would describe as coarse powder, those with significant proportions above about 100 mesh. A good example of coarse powder would be the powder used in the hot isostatic pressing of shapes and billets. These at one time could range up to 850 micromate for high speed steel billet production, but most producers now tend to use >600 or 500 micromate and much finer sizer are in use for more special alloys.