Freud DS0012S Diablo Bi-Metal Value Pack, 12-Piece Included are a 6 and 9-inch blades for nail embedded wood, 9-inch 18 and 24 tooth blades for metal, and a general purpose blade for wood/metal These specially designed blades include a variable tooth design for superior cuts in nail embedded wood, wood and metal Bi-Metal blades combined with Variable Tooth Technology gives up to two times longer life than standard blades. Special tip design allows for easier plunging in wood Special tip design allows for easier plunging in wood The Perma-Shield non-stick coating allows for less heat, gumming and corrosion