How to Use Your Grinder Safely and Soundly

The advantages of using grinding wheels are widely known. However, when grinding wheels that spin at thousands of revolutions per minute (RPM) are damaged or misused, they can break into bullet-like fragments, leading to injury. Grinding safety is a ...

AWS Publications | September 1, 2021 | Processes
Welding Digest ►  How to Use Your Grinder Safely and Soundly

The advantages of using grinding wheels are widely known. However, when grinding wheels that spin at thousands of revolutions per minute (RPM) are damaged or misused, they can break into bullet-like fragments, leading to injury. Grinding safety is a vast subject, with seemingly limitless tips, but the following offers just a few key guidelines to keep top of mind.

Lead photo: When used correctly, grinding wheels can help you achieve weld preparation, cut-off, and surface finishing safely and effectively.

 

Use the Right Machine Guard

Wheel guards help protect the user from sparks and debris during grinding as well as from broken fragments if the grinding wheel fails. Protective guards are crucial in keeping grinding wheel mishaps from leading to personal injury (Figure 1). As a result, guards are required by the Occupational Safety and Health Administration (OSHA) and should always be used.

Fig.1-4Figure 1: An operator is shown using a grinding wheel guard that extends far enough to keep debris and sparks away from his fingers.

 

However, hazardous conditions can also be created by the ineffective use of guards. Guards that are cracked, deformed, bent, or severely worn must be replaced. Once a guard has been damaged, it may become ineffective in catching broken fragments if the grinding wheel breaks. If wheel breakage occurs, the guard must be inspected, and if there is any sign of damage, the guard must be replaced.

Machines with missing wheel guard fasteners also pose a safety risk. Sometimes during routine machine maintenance, the guard fasteners are damaged and not replaced when the machine is reassembled. During a wheel breakage, the missing fasteners may allow the guard to move, become unattached from the machine, or open. This improperly attached guard may become a new hazard, exposing the operator to injury by the guard or not containing the wheel fragments in the event of a wheel break.

The operator should always use the guard that is recommended for the machine and its operation. A guard made of tin, cloth, wood, or other materials not designed to contain wheel fragments may fail when struck by a wheel fragment.

The illustration in Figure 2 provides more information on the proper use of guards.

Fig.2-3

Figure 2: These icons are designed to show the proper use of wheels and guards on a grinder.

 

Utilize Personal Protective Equipment (PPE)

In addition to following best practices for grinding tools, it is vital to protect the body using the approved PPE (Figure 3).

Fig.3-3Figure 3:  An operator wears flame-resistant clothing, eye and face protection, gloves, and ear plugs during grinding.

 

To protect against airborne sparks and metal chips, a face shield should be worn along with safety glasses that have a strap to prevent slippage. The operator should ensure that both the safety glasses and face shield fit well and won’t fall off or move around during grinding applications.

Wearing flame-resistant clothing and gloves to protect against burns and cuts is equally important. Gloves also absorb some of the vibration during grinding, which helps minimize operator fatigue.

Other PPE that should be worn includes ear and respiratory protection. Wearing ear plugs or muffs is beneficial in preventing hearing loss caused by noisy grinding operations. To protect lungs, at minimum, a dust mask should be worn, and some jobs will require that a respirator be used for even greater protection. Safety data sheets for both the material and abrasive wheel being used should be reviewed to determine the optimal respiratory PPE.

 

Choose the Correct Wheel for the Job

The correct pairing of a grinding wheel to the grinder is critical for safety as well as the success of the application. Every time a wheel is mounted or remounted onto a machine, the operator must check the wheel and machine’s speed to make sure the wheel is not operated in an over-speed condition. The abrasive wheel’s safe operating speed is marked on the wheel, and the machine’s normal operating speed is marked on the machine. The operator should never exceed the wheel’s safe operating speed. Failure to comply with this requirement is not only dangerous, it is also a violation of American National Standards Institute (ANSI) safety requirements and OSHA law.

 

Follow Proper Storage Procedures

Grinding wheels can become damaged and unusable before they are ever utilized. To avoid this, it is crucial to follow proper grinding wheel storage procedures. The following factors should be considered:

- All abrasive wheels should be stored in a dry area (away from water and solvents) in rooms not subject to extreme temperature changes because some abrasive bonds may be affected by humidity, dampness, and temperature differentials. Racks should be located as near as practical to the grinding location but never where there is danger of damage from passing trucks, crane handling, or excessive vibration.

- The racks, bins, and drawers should be constructed so that each of the various types of wheels can be stored in an orderly and safe manner. Wheel selection should be possible with minimal handling, and it is recommended to store wheels so that the oldest wheels in stock are used first. The selection of racks, bins, boxes, or drawers for storage depends on the size and type of wheels.

- Copies of all safety folders and notices should be prominently displayed in the storage area.

- After usage, proper storage of abrasive wheels is also important. Abrasive wheels must be removed from the grinder during overnight storage and while moving the machine from one location to another.

- When needing to place the machine down to do other tasks, a wheel/machine storage rack or other protective means should be used. Additionally, if the wheel is placed in a vulnerable spot, the operator may not be aware of damage that could have resulted while he or she was away.

 

Establish an Inspection and Maintenance Program

Maintenance of grinding tools and abrasives are paramount to productivity and safety. A good start and end to the day should include inspection of the tools being used.  All wheels should be inspected for breakage, nicks, or cracks. After inspecting the wheel and determining its integrity, the wheel should be run at operating speed for at least 60 s in an enclosure prior to grinding. It is also important to know that the inspection and testing of a grinding wheel is not a one-and-done task.

No matter the power type, cords and hoses should be inspected to ensure no damage has taken place since last use. The operator should also check for correct power source connections and settings. Proper, undamaged guards and flanges should always be attached. Any questionable parts should be repaired or replaced to ensure the safety of all personnel.

In addition to inspection, an effective maintenance program includes proper storage after initial use. It’s a good habit to remove abrasives from the tool after use and dispose of anything damaged. Leaving them attached allows someone to pick up the tool and use it with the possibility of something getting damaged without it being known to the next operator. Keeping unused abrasives in their proper storage box and designated location offers quick abrasives identification and helps prevent edges from being chipped or dinged.

Furthermore, it is recommended to use the original box for storage because it provides information for proper abrasives selection and safety protocols.

 

Conclusion

There are many guidelines for grinding safety, but following the simple recommendations listed in this article can help you avoid some of the most common hazards associated with grinding.

 

This article was written by Debra J. William (a senior product safety engineer at Norton|Saint-Gobain Abrasives, Worcester, Mass.) for the American Welding Society.