Sawtooth-profile nail

摘要

A plasterboard, boat, flooring underlayment or like ridged nail is provided with a taper of its sawtooth profile toward the point of the nail. The crests of the ridges can lie along one imaginary cone converging toward the point while the roots of the ridges lie along another imaginary cone equidistant from the first or converging toward the crest cone in the direction of the point. Steep-pitch helical flutes can be provided along the sawtooth portion especially when the nail is to be driven in hard materials.