Pack of 2 Blades - The Hyper Tough AU30011K 4-1/2 inch circular saw blade is ideal for all your cutting needs. This blade size has a 3/8 inch arbor and has been designed to fit the mini circular saws that require this size blade. The heat treated 24 TPI, ( Teeth per Inch), with tungsten carbide tips is buiIt for long life and durability and gives the versatility for fast clean cuts in most woods and various thicknesses The 24 tooth blade is used for frame cutting of soft woods, pressure treated lumber and MDF, hardwoods, plywood and moulding. The carbide blades come with expansion slots to minimize heat and vibration. This blade is rated for a no load speed of 13,200 MAX RPM.