What factors must be considered when selecting an abrasive wheel for grinding?

• A. The wheel color
• B. Material being ground, wheel grit, hardness, bonding, diameter, and RPM rating
• C. The brand name of the wheel
• D. The price per wheel

Answer: (B)

Choosing the right abrasive wheel hinges on matching the wheel to the workpiece and the grinding conditions. The material being ground dictates which wheel composition and abrasive type will work without excessive wear or heat. The grit size determines how aggressive the cut will be and the finish quality: a coarser grit removes material faster but leaves a rough surface, while a finer grit yields a smoother finish. The hardness of the wheel controls how quickly the grains are exposed and worn away; a wheel that's too hard can glaze on soft materials, while a wheel that's too soft wears quickly and reduces control. The bonding system holds the grains and affects wheel rigidity, heat buildup, and how the wheel wears and breaks down during use. The diameter must fit the machine and influences safe operating speed and surface speed. The RPM rating is crucial for safety—the wheel must be operated at or below its maximum rated speed to prevent failure. Color, brand, and price don’t determine grinding performance, so they aren’t the factors to prioritize when selecting a wheel.