What fraction of the stone should the guard on a pedestal grinder cover?

What fraction of the stone should the guard on a pedestal grinder cover?

• A. 2/3 of the stone
• B. 1/2 of the stone
• C. 3/4 of the stone
• D. 1/3 of the stone

Answer: (A)

Safety protection for the grinding wheel comes from having the guard cover most of the wheel, so fragments and sparks are contained if something goes wrong. A pedestal grinder should have a guard that encloses as much of the wheel as possible while still allowing you to use and dress the wheel. Covering about two-thirds of the wheel provides a strong protective barrier—most of the wheel is shielded, reducing the chance that a wheel fragment or hot debris will reach your body, while still leaving enough of the wheel exposed to perform the grinding task and access for maintenance. If the guard covered less than this, more of the wheel would be exposed and the risk would rise. If it tried to cover more, it could get in the way of proper operation. So two-thirds is the safe, practical guideline.

Safety protection for the grinding wheel comes from having the guard cover most of the wheel, so fragments and sparks are contained if something goes wrong. A pedestal grinder should have a guard that encloses as much of the wheel as possible while still allowing you to use and dress the wheel. Covering about two-thirds of the wheel provides a strong protective barrier—most of the wheel is shielded, reducing the chance that a wheel fragment or hot debris will reach your body, while still leaving enough of the wheel exposed to perform the grinding task and access for maintenance. If the guard covered less than this, more of the wheel would be exposed and the risk would rise. If it tried to cover more, it could get in the way of proper operation. So two-thirds is the safe, practical guideline.