The bead mill by Covington will make beads from 5/16″ to 3/4″ in diameter. The 4 1/2 diameter x 1/2″ aluminum head has a 3/8″ recessed ring in the ceiling which provides a trough for the beads to follow. Milling action is achieved by rotating the chamber while the head controls the beads location. The chamber head removes quickly for easy cleaning. This single speed bead machine runs at a set speed of 380 rpm and is best suited for agates, jasper and jade. Stock 1039BM, weight 75 lbs., dimensions 24″ x 12″ x 16″. Not recommended for gemstone material softer than a 5 on the Mohs scale as this machine is very aggressive. Please note the motor is 110V, 60 Hz, only. The 220V is not available for either bead mill. Covington Products are shipped from Meridian, ID.