These replacement Single-sided Hacksaw Blades are special shatterproof blades which are made of hi-carbon steel They offer superior cutting power and flexibility Having a flexible body, these 300 mm blades can cut through thick metal including steel, aluminum, copper and alloys The tooth line is made of high-alloyed super high speed steel, designed to give long life and excellent cutting performance To keep the blade life of this tool prolonged, use cutting oil