Solid and Hollow Configurations Available ~ square OD/ID, square OD/round ID, rectangle, hexagonal, octagonal, flutes in OD or ID, “B” shape, “D” shape, “I” shape, triangular, figure 8, hourglass, brush holder, dog house, mail box, skull shape, keyhole, bell shape, oval, flat oval, duplex, leak-detector, triplex, rifled ID, micro-wave guide. Consult mill for production of similar items.