Micro-Mill® Grinder. For fast, high-speed grinding of small samples from 20 to 50 mm (¾" to 2"). The unit comes with a stainless steel or hard-faced blade which rotates at speeds up to 12,000 rpm and will successfully grind bauxite, bone, ceramics, coal, Devorda's alloy, fertilizer, filter paper, fly ash, frozen tissue, glass, grain ...Web