The hammer mill door is interlocked with the rotor so no accidental opening is possible during operation. The grinding chamber offers complete access for wear part replacement and maintenance. Changing of screens and hammers is possible without the need for tools. Used BJD 668 Hammer Mill for sale at Engineering Services (London) Ltd. Used Bonfiglioli Drake 12 Hammer Shredder available from Engineering Services (London) ..... Approximate throughput 18-22 tons/hour (depending on material).