As consumers, we are always trying to get the most for our money – understandably. But, when it comes to cutting wheels, it can be overwhelming to evaluate all of the options. Adding to
that, it can be frustrating to not see an increase in performance or value, despite the effort put into making the selection.
That’s why it’s important to understand the causes of frequent challenges with using cutting wheels so you can troubleshoot faster and improve cutting performance. Read on to get answers to five wheel-related questions.
Why don’t my wheels last longer?
Answer: Several factors beyond the cutting wheel itself can affect wheel life. Pushing too hard, an underpowered or overpowered tool, or selecting a wheel that is too soft for the application, for example, can reduce the effectiveness and life of any cutting wheel.
Many operators assume that the harder they push, the faster the wheel will cut. The fact is, using too much pressure heats up the wheel, causing it to break down much faster. Remember to let the wheel do the work and cut with less downward pressure, incorporating a slicing motion through the cut.
It’s also important to choose a power tool with appropriate power and pair it with the proper wheel bond. The more torque your tool has, the more power it has to fracture the grains so they can maintain their sharpness.
You should also match the bond of your wheel to the material being cut. Less expensive wheels generally have softer bonds. Wheels with a softer bond cut faster and break down faster, reducing life. Harder bonds last longer but are more difficult to control. A good general rule to remember is the harder the metal, the softer the bond you want to use and vice versa.
Lastly, pay attention to the shelf life of your abrasive products; the abrasive that holds the wheel together starts to degrade after time. The wheel is still safe to use, but it won’t perform as well and should be replaced when outside of if its best-before date. It’s also important to store abrasives in a clean, dry location with a consistent temperature to prolong life because moisture and extreme temperature changes can affect the wheel bond.
Why do my wheels stop cutting after a while?
Answer: Glazing is often the culprit when wheels stop cutting and can occur when the grains dull due to increased heat and friction. This problem can be caused by using a wheel that’s too hard with an underpowered tool, not using enough motion through the cut or applying insufficient pressure.
Harder wheels require a tool with enough power to maintain maximum rpm, allowing the grain to fracture and self-sharpen. When this doesn’t happen, you may begin to push harder in an attempt to increase performance. If you can hear your grinder “bogging down” during use, the tool may not be effectively shedding dull grains to reveal fresh, sharp grains. This causes heat to build up and glazing may occur. If glazing is a common problem for you, choose a softer bond product, as it will break down with less pressure.
Not using enough motion through the cut is another cause of edge glazing. Use an even rocking or slicing motion with consistent pressure through the cut to reduce heat and friction that leads to glazing.
What causes arbor hole damage?
Answer: Damage to the arbor hole can be caused by excessive pressure, a workpiece that’s not properly clamped, improper mounting, product binding and vibration, or a combination of factors. Because damage to the arbor hole can weaken the wheel and cause failure that poses a safety risk, it’s important to always inspect wheels for damage before use.
To avoid arbor hole damage, check to ensure that the cutting wheel is mounted flat and flush with the adapting nuts or flange. Wheels should be mounted firmly, but overtightening can damage the arbor hole and the sides of the wheel. Most importantly, never assume that a wheel that is already on a tool has been properly mounted. Check the mounting prior to use by “jogging” the tool – while holding it away from your body, allow the wheel to come up to maximum speed three to five times.
Avoid pushing too hard on the wheel and maintain a 90-degree angle to the workpiece during the cut to prevent binding. A cutting wheel is designed to cut on its edge, so it doesn’t have reinforcement to support side grinding. Using the side of the wheel, as you would use a grinding wheel, damages the fiberglass reinforcement that holds the wheel together. Once a defect starts, it continues to grow and become more dangerous.
The workpiece should always be clamped firmly so it won’t vibrate during the cut. Position the workpiece so that you begin your cut as close to the clamp as possible while still allowing clearance for the guard, the tool and your hands.
Proper clamping and motion and maintaining a consistent, straight line all helps prevent binding and vibration during the cut.
What causes damaged wheel edges?
Answer: Mounting or using the cutting wheel improperly can result in damage, and even small cracks on the edge can quickly spread and cause the wheel to break apart. Remember that
because cutting wheels are very thin, dropping one – even from a very short distance – can lead to cracks and damage on the sides or edges. These small cracks and other damage can be difficult to see, so you should carefully inspect wheels before every use.
After looking for any obvious signs of damage, turn the tool on to jog it for about a minute while holding it away from your face and body. Look and feel for any vibration, unbalance or chunking, which are common signs of edge damage. If the wheel is out of balance, it’s likely damaged.
Never chip the edge of any wheel on purpose in an attempt to avoid glazing, because it can easily spread and cause wheel failure – posing a safety hazard.
Make sure the workpiece is properly clamped to help reduce excessive vibration or chatter that can lead to edge damage. Again, your cut line should be as close to the clamp or mounting point as possible to reduce vibration and increase cutting efficiency.
Never use a cutting wheel for grinding because the two products are designed and reinforced for different uses, angles and techniques.
How much pressure should I use?
Answer: Too much or too little pressure can be the cause of many common problems in metal cutting, including shortened wheel life, edge glazing, arbor hole damage and more. Using proper pressure is one of the most important best practices to optimize performance and results with cutting wheels.
Too much pressure heats up the wheel, causing it to break down much faster. Increasing pressure also adds stress to the sides of the wheel, making it harder to control. Lastly, overpressuring a wheel can cause the wheel to flex in the cut line, which can lead to binding. If the wheel does bind, the kickback is likely to be more violent if you are using excessive pressure.
Moderate pressure that lets the wheel and the cutting grains do the work results in much faster and smoother cutting action. Cut with less downward pressure and incorporate motion through the cut.
If you feel yourself needing to apply too much pressure – and you can hear or feel the rpm dropping or fluctuating – switch to a softer bond wheel. If you are cutting thin-gauge material, you might consider a 1-mm cutting wheel instead of a traditional 0.045-in. wheel.
Too little pressure can also result in problems like edge glazing. The wheel may skip and chatter rather than bite and cut when not enough pressure is used. It’s always best to use consistent pressure through the cut and a smooth and even rocking motion.
Overall, when cutting metal with hand-operated tools, it’s not uncommon to encounter problems that can cost time and money – and pose safety hazards. Before operating the power tool, always read the enclosed instructions for safe and proper use.
Understanding best practices for using cutting wheels can help you identify issues that arise and determine the right solution. Using wheels properly and following recommended techniques can help improve performance, efficiency and safety.