Tiger Aluminum 4.5 inch type 27 depressed center cutting wheels are specifically designed for high performance cutting and extended wheel life on aluminum. These wheels blend abrasive grains with WeilerĂs non-loading formula, resulting in a fast and consistent cut rate on aluminum. The depressed center provides added clearance when working at a constrained angle. Wheel thickness of .045" is ideal for cutting tubes, bar stock and large cross-sections with a right angle grinder. Small 5/8" - 11 nutted metal hub reduces gouging of the workpiece and allows for 30% more usable surface area of the wheel in addition to providing quick spin-on, spin-off changeover of a standard hub.