Bi-metal made iron saw blades are way tougher than regular iron saw blades and it's almost impossible to break them. Precision-ground teeth boost the blade's durability and performance when cutting most hard materials. The blade fits 300 mm (12") iron saws. 24 TPI (teeth per inch) bi-metal saw blade can be used for sawing most hard materials. The blade works best on 2 - 5 mm thick: aluminum, bronze, copper, brass, hard plastics, cast iron, steel, and stainless steel.