The high speed steel u-slot undercutting saws are carefully designed as to tooth form, hollow grind, hardness, etc. and are manufactured to close tolerances. While used primarily for undercutting mica and slotting risers of commutators, Martindale undercutting saws are also used for cutting steel, aluminum, plastics and other materials not requiring set teeth. - The teeth of u-slot undercutting saws have a slight land to give strength to the cutting edge. These can be used on either portable or stationary equipment.