type of hammer mill,Hammer mill by Saraswathi.B - PharmainfoOpenings in perforated screens or grate bars; Number, size and type of hammers; Grinding plate setting; Rotor speed. Hammer mills. Based upon the speed and the cutters used in hammer mill produces very fine ultra sized particles. This are mainly operated at 2500 rpm or 1000 to 2500 rpm for the reduction of the large.type of hammer mill,Hammer Mill Crusher & Grinder - 911 MetallurgistMar 12, 2018 . It is hardly necessary to state that the size of product directly affects the capacity of a hammermill, just as it does any type of crusher. The finer the product the more work the machine must do; furthermore, the grate bars, when any are used, must be spaced closer, which means that the open area of the grate.