The tooth chisel is a metal hand-held tool consisting of a shaft, 16-22 cm long and 1-2 cm in diameter, with a toothed cutting edge at one end typically 0.5-10 cm wide. It is again usually hit with a metal hammer or sometimes a mallet. The number of teeth on this cutting edge varies, usually between three and five, but a variation with two teeth also exists. The tooth chisel is usually used between roughing-out and finishing, to clear away the rough marks left by the point chisel and prepare the surface for finer work with the flat chisel. While the tooth chisel is usually an intermediary tool it was occasionally used in the Roman period (and more later) to apply texture, especially on large expanses of flat surfaces where a smooth finish was not required.
Typically the tooth chisel is held at 35-60° to the surface of stone and leaves behind characteristic sets of shallow parallel lines. Sometimes it is held closer to the vertical to cut into the stone more in which the marks left behind are less regular. The shape of the actual teeth on tooth chisels will also obviously affect the marks they leave behind. The tenth can be either pointed or squared, with sharper ones preferred for marble carving and blunter ones for limestone carving. Tooth chisels are not used on granite because their teeth would break.
