Norton Abrasives Grinding Wheel, Gemini Fast Cut Grinding Wheel, 4 1/2 for Ri…
Depressed center wheels may also be referred to as raised hub wheels or by their shape designation Type 27, 28 or 29, with Type 27 being the most popular. The depressed center design allows the flange/lock nut to recess within the wheel so that it can be used for various grinding and cutting applications.