SECTION 7.11

Grinding wheels improperly used are dangerous, but grinding is a safe operation if the few basic rules listed below are followed. These rules are based on material contained in the ANSI B7.1 Safety Requirements for the "Use, Care, and Protection of Abrasive Wheels".

Mounting. Correct mounting procedures are essential to the efficient and safe operation of the wheel. It is important that personnel performing the function are fully competent.

Do:

1. Visually inspect all wheels before mounting for possible damage.
2. Check machine speed against the established maximum safe operating speed marked on the wheel.
3. "Ring" the wheel to determine if it is free from cracks.
4. Use one clean blotter on each side of the wheel.
5. Check mounting flanges for equal and correct diameter (generally 1/3 diameter of the wheel).
6. Tighten multi-screw flanges uniformly to the machine manufacturer's suggested torque with a torque wrench.

Do Not:

1. Mount a cracked wheel or one that has been dropped or has become damaged.
2. Use wheels whose maximum r.p.m. is less than the r.p.m. of the machine spindle.
3. Force a wheel onto the machine or alter the size of the mounting hole. If the wheel doesn't fit the machine, get one that will.
4. Use flanges of unequal diameter or relief, nor those which are not clean, flat, or free of burrs.
5. Over-tighten flange retaining nuts.

Order of Tightening
1 - 2 - 3 - 4 - 5 - 6

Use. Given the correct wheel, mounted in accordance with approved procedure, safe operation depends largely on the treatment to which the wheel is subjected during use.

Do:

1. Ensure that guards and workrests are properly adjusted and secure before starting the machine.
2. Always use a safety guard covering at least one-half of the grinding wheel.
3. Allow a newly mounted wheel to run at operating speed with the guard in place at least one minute before staring to dress or grind.
4. Always wear protective glasses or some type of eye protection when grinding.
5. Always dress or make grinding contact gently.
6. Re-dress the wheel whenever necessary.
7. Turn off the coolant before stopping the wheel to avoid creating an out-of-balance condition.

Do Not:

1. Ever exceed the maximum operating speed established for the wheel.
2. Start the machine until the guard is in place.
3. Stand directly in front of the wheel when the machine is started.
4. Jam the work into the wheel, nor use excessive pressure or infeed.
5. Force grinding so that the motor slows noticeably or the work gets hot.
6. Grind on the side of the wheel (see safety code exception).
7. Allow stationary wheels to rest in fluids.
8. Apply pressure to wheels to stop them.
9. Continuously use glazed wheels without dressing.
10. Use wheels for purposes other than those for which they are designed.

Storage. Suitable racks, cradle, and drawers should be provided to store the various types of wheels used. The sketch shown on the next page indicates a typical rack storing a range of wheels.

Do:

1. Store wheels correctly supported.
2. Stack thin wheels flat.
3. Ensure storage in dry conditions.

Do Not:

1. Store in damp or humid conditions.
2. Subject wheels to dramatic change in temperature.
3. Subject wheels to temperatures at or approaching freezing.