Medium—Medium-hardness wheels conform to surfaces better than hard-density wheels. Use for blending tool marks, light deburring, and creating a bright surface finish.

Hard—Hard wheels are more durable for aggressive material removal and heavy deburring.

For Steel, For Stainless Steel, For Aluminum, For Brass, For Bronze, For Copper, For Iron, and For Nickel—Sets for steel, stainless steel, aluminum, brass, bronze, copper, iron, and nickel contain bits made from a range of abrasive materials in different shapes and sizes. They’ll help you achieve varying levels of finish on a wide range of materials. Cotton laminate/aluminum oxide blend bits remove more material than rubber-cushioned aluminum oxide bits, and they’ll create a nicer finish than vitrified ceramic alumina bits. Bits with nylon mesh remove the least material but create the nicest finish.