Angle grinders are versatile power tools that can be used for cutting, grinding, polishing, and sanding various materials. They come in different sizes, ranging from 4 inches to 9 inches, depending on the disc diameter. However, not all angle grinders are safe to use, especially the larger ones. In fact, some work sites have banned the use of 9 inch angle grinders due to the increased risk of injury and death. But why are 9 inch angle grinders banned? What makes them so dangerous? And what are the alternatives to using them?
The main reason for banning 9 inch angle grinders is that they are more prone to cause severe kickback and gyroscopic effects, which can result in the disc shattering and injuring the user or others nearby. Kickback occurs when the disc gets jammed or pinched by the material being cut or ground, causing the grinder to recoil or jerk violently. Gyroscopic effect occurs when the rotating disc creates a force that makes the grinder difficult to manoeuvre or control. These effects are amplified by the increased power and size of the 9 inch angle grinders, which also make them heavier and harder to handle.
One of the most common causes of disc failure is the use of incorrect or damaged discs on the angle grinders. Some workers may use cutting discs that are too large for the angle grinder, such as fitting a 14 inch disc on a 9 inch grinder. This increases the edge speed of the disc beyond its designed limit, making it more likely to break or shatter. Another cause is the use of cutting discs for grinding purposes, which can wear out the disc faster and create more friction and heat. Additionally, some workers may remove the guards or use the wrong flange or nut to secure the disc, which can compromise the stability and safety of the grinder.
There have been several fatal and serious incidents involving 9 inch angle grinders in the past few years. For example, in 2016, a worker in Queensland, Australia, died when a broken disc struck his chest and caused deep cuts. In 2015, another worker in Australia died from an electric shock while using a 9 inch grinder. In 2014, a worker in New Zealand lost his eye when a disc exploded and hit his face. These incidents have prompted many work sites to ban the use of 9 inch angle grinders and implement stricter safety measures.
The alternatives to using 9 inch angle grinders
The best way to avoid the risks associated with 9 inch angle grinders is to use smaller and safer alternatives, such as 4 inch or 5 inch angle grinders. These grinders are easier to control and have less kickback and gyroscopic effects. They also require less force and pressure to operate, reducing the fatigue and strain on the user. Moreover, they are more suitable for precision and detail work, as they can access tight spaces and corners.
However, if the use of 9 inch angle grinders is unavoidable, there are some precautions that can be taken to minimize the hazards. These include:
Always use the angle grinder with the correct guard supplied by the manufacturer.
Always use the right sized disc that matches the spindle flange and the maximum speed of the grinder.
Always use the tightening tool provided by the manufacturer to secure the disc properly.
Always use the appropriate disc for the intended purpose, such as cutting or grinding.
Always inspect the disc for any cracks, chips, or damage before use.
Always wear the appropriate personal protective equipment, such as gloves, goggles, ear plugs, and dust mask.
Always hold the grinder with both hands and use the side handle for extra grip and stability.
Always keep the grinder away from your body and other people.
Always let the grinder run at full speed before applying it to the material.
Always switch off the grinder and unplug it when not in use or changing the disc.
9 inch angle grinders are banned on some work sites because they pose a high risk of injury and death to the user and others. They are more likely to cause kickback and gyroscopic effects, which can lead to the disc shattering and flying off. The main reason for this is the use of incorrect or damaged discs on the angle grinders, which can exceed the speed and capacity of the grinder. The best way to avoid these risks is to use smaller and safer angle grinders, such as 4 inch or 5 inch ones. However, if the use of 9 inch angle grinders is necessary, some safety measures can be followed to reduce the hazards. Angle grinders are powerful tools that can be useful for various tasks, but they must be used with caution and care.
