Video: Grinding Wheel Safety–It's the Smart Thing To Do

Faster than a speeding bullet and just as deadly is exactly what the fragment of a broken grinding wheel can be. Because grinding wheels do such tough work, it's easy to think that grinding wheels can take as much abuse and misuse as we can dish out. The grinding wheel works so well on some of the toughest jobs they're often referred to as blaze, rocks or even stones. It's easy to mistakenly think that they are nearly indestructible. The fact is a grinding wheel is actually a man-made tool that is made up of thousands of small abrasive cutting grains that have been bonded together by an organic resin compound. While the jobs they perform allow you to effectively grind, form and finish the toughest materials, grinding wheels can become damaged if handled improperly.

Moisture, extreme temperatures and rough treatment can damage your grinding wheel. The most important thing for us to remember when using a grinding wheel is that if damaged or misused, a grinding wheel can be as dangerous as a bullet. It is very important that you know what safety precautions need to be taken as well as how to properly use the grinding wheel.

Safety is a critical concern long before you begin to grind. With a commitment to excellence and total quality, Norton Company takes great pride in providing you a safe, effective tool. So it is critically important that all abrasive wheels be protected while waiting to be used. Wheels not stored properly can be damaged, damage that may go undetected by conventional means of inspection until they are put into use.

Storage should be arranged to allow for the removal of wheels without disturbing other wheels. Wheel stock should be rotated to minimize the possibility of damage from lengthy storage. Suitable racks, bins, drawers or boxes must be used to store the various types of wheels. Wheels should never be stored where they will be exposed to water, solvents, extreme cold temperature, or humidity conditions that cause condensation on the wheels.

We recognize the value of a good safety program. We believe that safety is the foundation of our reputation combined with our productivity and quality. We believe the success of our safety program is within each and every one of our employees participating in our safety program. Your personal safety and the safety of your co-workers always begins with you. Choosing to wear the proper safety equipment such as a hard hat, authorized safety glasses, face shield, gloves, leather apron, arm guards, safety boots and earplugs will make your job safer and increase your productivity.

Read and review on a regular basis the ANSI B7.1 manual of safety requirements for the use, care and protection of abrasive wheels. Compliance with OSHA ANSI B7.1 and the safety guides packed with grinding wheels is required. A copy of these publications may be obtained free by writing to the manufacturer printed on the wheel.

The size and operating speed of the grinding wheel you choose to work with are the next important steps to maintaining a safe work environment. Never choose a grinding wheel that is too big for the machine you have chosen to use. To make this wheel fit on this machine, the guard and mounting flanges would have to be altered, making the machine unsafe to operate. Always use the grinder as it is intended to be used— a 7 inch wheel on a machine designed for 7 inch wheels, and the 4 ½ inch wheel on a machine designed for 4 ½ inch wheels.

A proper guard is really important on a grinder because one time I saw a grinding blade come apart and all the fragments that were flying would have hit the guy in the face or in the body and they protected his body and face both. So it's really important to have a proper guard on your grinder at all times.

Never attempt to mount a cut-off wheel on a right angle grinder that is not specifically designed, guarded and has the proper speed for cut-off wheels. Only use reinforced cut-off wheels specifically designed for use on the right angle grinder. Before you mount a grinding wheel, check the speed of the machine and make sure the wheel you select is designed to operate at the same speed or higher than the machine's rated speed. Do not use a grinding wheel on a pistol grip air sander or any other machine not specifically designed and guarded for type 27 or type 28 wheels. Do not use grinding wheels on machines with RPM ratings higher than the speed marked on the wheel. Mounting a grinding wheel on a machine that is not designed for grinding wheels can cause serious injury or even death.

When mounting the grinding wheel on your machine, the first thing you always want to do is unplug your machine before removing the old grinding wheel. Prior to mounting a grinding wheel, carefully inspect it for any damage. If you think the wheel has been damaged, do not use it. Under no circumstances should you use a damaged grinding wheel. Check the wheel speed and the machine speed. Make sure the flanges are clean and in good condition. Once the grinding wheel is mounted, reconnect the machine. Adjust the guard if necessary and place it in an enclosed area and allow it to run for one full minute. If the wheel was damaged in transportation or handling, it will most likely break in the enclosed area. When a discard mount is not already attached to the grinding wheel, a reusable kit mount can be used to mount a type 27 or type 28 wheel. The reusable kit mount comes with the back flange, bottom flange and Allen wrench for tightening the bottom flange. This operator is using a type 27 wheel on the grinder. Washers are included in the kit that will allow you to mount a ¼-inch, 1/8-inch and 3/8-inch thick wheels. This mount can be used many times before it needs to be replaced. A bent, worn out or damaged mouth should be discarded.

This operator is using a 4 ½ by ¼ inch type 27 wheel properly. All of the grinding is on the bottom of the wheel at a slight angle to the work. Never grind on the top of a type 27 wheel. This machine is properly guarded and adjusted so the guard is positioned between the operator and the grinding wheel. Never use excessive side pressure or bump a type 27 grinding wheel. Always be certain that no one is standing in the spark stream during the grinding operation. Care should be taken to shield any flammable material. This is a 9 by ¼ inch type 27 grinding wheel. Notice he is grinding on the correct surface. The guard is properly placed between the grinding wheel and operator. When this operator is done grinding, he will allow the wheel to come to a complete stop and place it in a safe storage rack. This storage rack is a permanent fixture and part of this workbench. When a machine and wheel are put down, even for a short period of time, they must be stored correctly. They must never be dropped or placed where they could be pulled off of a table or bench onto the floor, as this would damage the machine and the grinding wheel. If the machine is set on the workbench and has accidentally knocked off of the table and damaged, the operator could come back and start the machine not realizing what has just happened. If the wheel or machine had been damaged, the operator could have been seriously injured. This is the cause of many grinding wheel accidents. If you know a machine and wheel have been dropped, the wheel should be removed from the machine, inspected, and discarded if damaged.

Type 28 wheels have saucer-shaped grinding rims and they're designed for applications where a very shallow angle is required or for side grinding. The type 28 wheels should never be used for cut-off or notching operations. In this application, an 1/8 inch thick type 27 grinding wheel is being used. The outer periphery of the grinding wheel is doing the work. This wheel is designed for getting into tight places. Care must always be taken to avoid excessive side pressure or jamming the wheel. With this thinner type 27 wheel, excessive side pressure can cause this wheel to break.

To keep your work environment as safe as possible, there should be a regular scheduled maintenance program for all grinding machines. ANSI recommends that electric grinders be checked monthly. Machine speed should be checked after any maintenance, repair or if anyone suspects the machine's speed may be incorrect. Before checking, disconnect the machine from its power source, remove the grinding wheel and any loose objects from the spindle. Next, mark the spindle with reflective tape at a location where you can clearly read the machine speed. There is more than one type of tachometer. In this demonstration a photo tachometer is being used to check the speed. Plug the machine back in and direct the light beam at the tape. Start the machine and take a reading. The speed reading, along with the date and serial number of the machine, are recorded. Careful logs of the machines promote proper maintenance and allow you to see when the machine speed changes over a period of time.  Both electric and pneumatic grinders must be maintained on a regular basis. ANSI recommends that air driven or pneumatic portable grinders be checked after 20 hours of use or once per week, whichever comes first. As with electric grinders, remove the wheel and loose objects from the spindle. Apply reflective tape to the spindle. The reading, along with the date and serial number of the machine, will be recorded in a log.

Proper air pressure on pneumatic machines is critical to your safety. If the machine is built and designed to operate at 90 PSI, the air regulator at the workstation must be set to 90 PSI or less. An improper setting on the regulator could cause the machine to operate in an overspeed condition, putting the operator and bystanders at risk.

The grinding wheel is one of the most widely used industrial tools. Coupling this powerful tool with simple safety guidelines can make your job easier, safer and more productive. Always wear the proper personal safety gear. Always use a properly guarded machine. Know the ANSI safety guidelines. Inspect and test all wheels before using. Select the right wheel size and speed for the right machine. Always cradle a machine in a permanent storage rack when not in use. Make sure all of the machines are inspected and maintained on a regular basis. Remember, you are as safe as you choose to be. Choose to follow the safety guidelines. It's the smart thing to do.