Unv no. 4 kerf .042 TPI 36 144 same spec blades per pack. Spiral Tooth blades saw in all directions with 360º cutting capability. Excellent for 0º radius scroll/fret work you never have to turn the workpiece. For cutting wood, plastic, wax, non-ferrous metals, plaster, bone, horn, etc. For use in power scroll saws and hand-held fret and jewelers saw frames. Cutting speed and finish depend on material thickness and number of teeth per inch. These premium blades are made of high carbon steel, hardened and tempered to stay sharp longer. Good for bevel cutting letters in names. Increase throat capacity and cut longer pieces without turning.