Straub Model F4. hand operated for crushing grain or feed samples, also any dry chemicals or ores. Largest capacity, easiest operating hand mill available. Grinder construction is sturdy cast iron. Optional coating for food applications. 316 stainless steel. construction available. Grinding plates are made of hard iron alloy designed for clog resistance and long life. Plate clearance easily adjusted by hand to change mesh. Choice of 4-B Plates for fine grinding or 4-CS Plates for coarse grinding. Choice of Tooth Feed for dry grinding or Worm Feed for wet or oily grinding.