1.Material:Spring Steel 65Mn,SUP6 2.HRC:38-45 3.Plain Disc and Notched Disc 4.Diameter:12"-30" 5.Excellent Wear Resistance Our Disc Blades are available in various diameter ranges from 12 inches to 30 inches with differing in concavity and thickness.The main types of blades are Plain Disc and Notched Disc. And the punches of center hole include round,square,hex,octave,round with key slot,round ...