Dental chisels come in a variety of shaft lengths and blade dimensions. Chisels, including hoes, angle formers, and discoid and cleoids (disk- and claw-like double ended chisels), are used for planing and cleaving enamel. They feature blades that terminate in a cutting edge and are often used in cavity preparation, to shape and refine, and for amalgam and wax. Hatchets feature angled heads, as opposed to the straight blade and shaft of a chisel, and are also used in cavity preparation.