Tiger® Zirc 4-1/2 in type 27 depressed center Cutting Wheel cut faster and last longer so you get proven productivity at an exceptional total cost. The self-sharpening zirconia alumina grain retain a high cut rate throughout the life of the wheel while a hard bond delivers long wheel life for heavy duty application. The flat profile of the wheel in combination with depressed center allow for a wide range of grinding angle (0 to 45). The 0.045 in wheel thickness is ideal for cutting tube, bar stock and large cross section with a right angle grinder. The small 5/8-11 UNC nutted metal hub reduce gouging of the workpiece and allow for 30% more usable surface area of the wheel in addition to providing quick spin-on, spin-off changeover of a standard hub. These wheel are designed for hardcore metal fabrication professional who need a high performance solution when cutting steel, structural steel and iron. Tiger® Zirc Cutting Wheel, Fast Cut Long Life High Performance, 4-1/2 in Wheel Diameter, 0.045 in Wheel, Hub Connector, 60 Grit, Z60T Grade, Wheel Type Number: Type 27, 13300 RPM Maximum, Hard/Resin Bond, Applicable Materials: Iron/Metal/Structural Steel, 5/8-11 UNC Center Hole Thread, Wheel Hardness: T, Reinforced: Yes, Specifications Met: ANSI B7.1