A chisel is a tool for chipping or carving some surface, consisting of a metal bar with a sharpened edge at one end. It’s a period charge, found in the canting arms of Cheseldene, 1413 [DBA2 401].
Parker  says that the stonecutter’s chisel is the default form; however, period rolls [e.g., the Fenwick Roll, temp. Henry VI; Bedingfeld 61] show the wood chisel instead. The exact type should therefore probably be specified. There doesn’t seem to be a default orientation for all chisels; the Society has defined the default for wood chisels to be with their edges to chief. The illustration shows both chisels so drawn. See also awl, graver.
Jón trételgja Ljótsson bears: Sable, three wood chisels argent.
Sigurðr inn danski bears: Or, a wood chisel, blade to chief, sable.
Stiamna mac Martain bears: Vert, four wood chisels bendwise sinister blades to chief two and two Or.