The tomahawk shaft is usually less than 2 ft (0.6 m) in length, traditionally made of hickory. The heads are anywhere from 9–20 oz (255–567 g) in weight, with a cutting edge usually not much longer than four inches from toe to heel. The poll can feature a small hammer, spike or simply be rounded off, and they usually do not have lugs. Stone tomahawk heads were typically made of polished soapstone, and ornately carved examples were used in some Native American rituals. These usually had a pipe-bowl carved into the poll, and a hole drilled down the center of the haft for smoking tobacco through the tomahawk. There are also metal-headed versions of this unusual pipe. Pipe tomahawks are artifacts unique to North America: created by Europeans as trade objects but often exchanged as diplomatic gifts. They are powerful symbols of the choice Europeans and Indians faced whenever they met: one end was the pipe of peace, the other an axe of war