Best Practices for Cut-off Wheel Safety with a Variety of Wheel Diameters

Safety in a manufacturing environment is everyone’s responsibility — and cut-off wheel safety is especially important since these abrasives are used on tools that run at high speeds. 

When a user uses a cut-off wheel incorrectly or uses a damaged wheel, it can break apart and throw sharp projectiles at a high-speed rate. 

This makes it critical to pay attention to the condition of cut-off wheels and follow best practices to use these products safely and efficiently. Consider some tips for safely using small, standard, and large cut-off wheels.

General cut-off wheel safety recommendations

• Wear the necessary Personal protective equipment (PPE): Personal protective equipment should be worn when using a cut-off wheel. PPE includes safety glasses, a face shield, ear protection, gloves, flame-resistant clothing, a leather apron, and safety shoes. Hard hats and/or welding caps can also protect the head from sparks during metal cutting. 
• Conduct a visual inspection: Inspect the cut-off wheel and tool before use. Replace with a new wheel if there are cracks or other signs of wear or damage. Even if the wheel is still on the tool, the tool could have been dropped or knocked off the tool rack, so it’s important to always check for damage before use. Also, jog the tool for a few seconds before using it to ensure it’s running true. 
• Mount the wheel correctly: Most cut-off wheels have a stamped metal ring around the wheel hub. The wheel should be mounted with that stamped insert facing the spindle on the motor side of the tool. This will provide a flush mount because there is less chance for grit or abrasive debris to be present on that side of the wheel. 
• Secure the workpiece: Be sure the workpiece is held tightly in a vice or clamped so there’s no chance it will move, bend, or roll once the cut is started. If the workpiece moves during the cut, it could twist and pinch the wheel, potentially causing it to break apart. 
• Don’t flex a cut-off wheel: During a cut, never try to flex or bend the wheel to make a curved cut. This introduces side loading and can fracture the wheel.  
• Never grind with a cut-off wheel: A cut-off wheel doesn’t have the fiberglass reinforcement that a grinding wheel does, so it can be dangerous to grind with a cut-off wheel. Only use a cut-off wheel for cutting. Combination wheels can be used for cutting and grinding and are marked accordingly. 
• Don’t push a wheel through a cut: Cut-off wheels should only have the weight of the tool as they go through a cut. Forcing the wheel with unnecessary pressure can cause the wheel to slip and bind. Too much pressure also decreases product life.
• Use a better abrasive for harder materials: Some specialty metals like titanium or Inconel can be difficult to cut. In these cases, choose a cut-off wheel with a higher-performing abrasive grain like a ceramic. This helps you cut efficiently and reduces the possibility of the wheel glazing due to excessive heat.  
• Watch the spark path: Sparks are created with any type of cut-off wheel. The spark path can be altered depending on the approach used for the cut. Be mindful of the spark path and any items that could be damaged or coworkers who are in the area.

Best practices for small-diameter cut-off wheels

Wheels with 100 millimeters or less diameter and 6- or 10-millimeter arbor hole size are considered small-diameter wheels.

Small-diameter cut-off wheels are frequently used in metal fabrication, shipbuilding, and numerous other manufacturing industries. The smaller size of these wheels is a benefit when cutting metal in a corner or hard-to-reach spot. 

Some users may feel overconfident with a smaller diameter wheel — thinking they will be easier to control. But many of the pneumatic tools in this size range can run at much higher RPMs, so be careful to use proper cutting techniques and always use the tool guard. Also, be sure the speed rating of the wheel matches or exceeds the speed rating of the tool.
 
Just because a wheel can be mounted on a die grinder doesn’t mean it is safe to do so. There are many dedicated small-diameter cut-off tools available that include proper guarding. Make sure you have the appropriate tool and guard before you start cutting. 

Best practices for standard diameter cut-off wheels

As these wheels wear down, they can become harder to control. When a wheel becomes too small to properly control or make the desired cuts, swap it out for a new wheel. 

Best practices for large-diameter cut-off wheels 

Wheels with diameters ranging from 250 to 610 millimeters fall into the large-diameter category. The most commonly used sizes of large wheels are 305, 356, and 406 millimeters. 

Large-diameter cut-off wheels are often used to cut thicker or larger pieces of metal. They are typically used on tools like chop-, stationary-, or high-speed saws. For large-diameter cutting wheels, it is also important to distinguish between the tools they can be used with. For example, with table circular saws, it is preferable to use thinner products (around 3 millimeters thick), as these allow them to pass through the material more easily when cutting. When working with stationary saws, use slightly thicker wheels (between 3,5 and 4,5 millimeters), which have a better/stronger reinforcement than thinner products. As stationary saws are stronger, damage can occur when using a thinner cutting wheel, especially when used at high speed. However, observing the pictograms on the products when using petrol cut-off saws is essential. The use of certain wheels in combination with these tools is prohibited. Due to the three possible directions of movement and the associated possible additional pressures, this tool can only be used with triple-reinforced fiberglass wheels. It is, therefore, always necessary to read the label on the product before starting work.  

Be sure to match the wheel's speed, size, and recommended application to the speed and size of the specific tool being used. Also, ensure the wheel uses the proper abrasive grain for the metal being cut and that it’s designed for that tool. Using the wrong abrasive can generate excessive heat and cause the wheel to glaze and stop cutting.

Safe use of cut-off wheels 

WEILER ABRASIVES SAFETY PROGRAM - SPOT:

Abrasives and power brushes can pose a serious safety risk when used on angle grinders and other power tools. The Weiler Abrasives SPOT Safety Program focuses on the principles of SPOT (speed and size, pressure, orientation, time) to promote and educate users on the safe and proper use of abrasives.

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