Safe Use of Grinding Wheels
The speed at which many grinding wheels operate renders it necessary for us to use them carefully. We must know what we are doing—trial and error is too costly.
Here are some important directions for safe handling of a grinding wheel. See that your employees know them, and that they follow every one of them:
- Always keep your eyes protected. Be sure to put on your safety goggles before you start the wheel. Eye protection comes first. Use a face shield. See that the glass reflector shield is securely in place on the grinder, and that it is not cracked.
- When you start to use the grinder, make absolutely sure it is not already running. Once in a while somebody forgets to turn it off and it is generally hard to tell whether or not the wheel is actually turning.
- Check the work rest. It should be 1/8 inch from the wheel surface—no more. If further away, your work piece or fingers may get the work caught between the wheel and the rest. Then your hand may be dragged against the wheel or the wheel may burst.
- Check the flanges. Make sure there is a flange on each side of the wheel, and that both flanges are the same size. See that there is a washer of paper, rubber or leather between the flange and wheel, and that it is at least as large as the flange.
- Check the safety guard to be sure it covers the spindle end, nut, and flange projections. The safety guard should be mounted so as to maintain proper alignment with the wheel, and the strength of the fastenings should exceed the strength of the guard.
- Check the tongue guard. As a wheel wears down, the space between it and the guard increases. Where a wheel is equipped with an adjustable tongue, the space between the bottom edge of the tongue and the wheel face should not exceed 1/4 That is to confine the pieces should the wheel burst.
- When you have observed all of these points you are ready to start: Stand aside when you turn the power on, to play it safe should anything go wrong. Let it run a few moments to warm the wheel, and then check for unusual vibration.
- When applying your work to the wheel, be sure you have a firm grip. Apply it gradually to give the wheel a chance to expand evenly. Use moderate, even pressure, and don’t crowd the wheel. Don’t grind on the side unless the wheel is designed for it.
- Finally, be sure to turn off the power when you have finished your job, or if you leave the wheel even for a short time.
When wheels are received they should be carefully inspected for damage and given a ring test before storing. A ring test should be given again before wheel is mounted. Attention must be paid to where and how wheels are stored. Wet wheels have been known to break or crack when stored at freezing temperature.
When taking wheels out of storage, make sure you get the right wheel for the job you have to do.
Should a wheel break, the cause should be ascertained and the immediate inspection made to make sure the guard has not been damaged nor the spindle and the flanges sprung out of true or out of balance.