Putting YOUR safety first with practical tips on choosing the best abrasives 

Grinding Techniques: With the safety of our customers a top priority, we are determined to bring the best possible abrasives to the market, manufactured to the highest safety standards at the best value for money price-point. 

Product marked to indicate qualities and benefits

Conventional right-angle grinders are available in various diameter sizes ranging from 100mm up to 230mm, with the 115mm and 230mm ranking as the most popular.  

Being a very powerful and useful tool, it can potentially be very dangerous if not used correctly.  

Selecting both the correct size machine and abrasive product, is essential to ensure a safe operation.  

Attempting to utilise a 230mm diameter machine for grinding welds on palisade fencing would undoubtedly result in an  endeavour. The same can be said when using a disc too large for a given machine (ie using a 125mm diameter disc on a 115mm diameter machine), as it will run at a much higher speed than rated for, potentially resulting in a very dangerous operation. For easy reference, disc size diameters are clearly displayed on their labels. 

Apart from selecting the correct sized disc and machine, power and speed of the angle grinder also plays a significant role. POWER refers to the measurement of input or output wattage that the machine uses (depending on the manufacturer), where SPEED on the other hand, is clarified as the rate at which the disc will turn (measured in metres per second and stated as the RPM). 

Generally, the rule of thumb is that a higher power rating ensures a better performance of the abrasive product. Essential to keep in mind, is when an abrasive disc is cutting or grinding, it is putting additional load on the machine. If the machine is under-powered, the extra strain may cause a reduction in motor speed, causing potential damage to the machine and possible under-performance of the disc 

Important to note is that the maximum operating speed of a standard cutting or grinding disc is 80 metres per second (peripheral speed). Depending on the size of the disc, this will then relate back to a higher or lower RPM rating – 80m/s on a 115mm disc equates to 13 300 RPM, while 80m/s on a 230mm disc equates to 6650 RPM – matching an angle grinder only with a disc sized particularly made for that machine is considered one of the most crucial safety factors. 

Another factor to consider would be the standard accessories. All angle grinders should have a safety guard always fitted to the machine, a handle, and a retainer nut for securing the disc. Retainer nuts are available in various types for fitting the disc to the machine, including some that don’t require a spanner to fasten and loosen. Regardless of which type, make sure to avoid over tightening as these machines are designed to self-tighten on start-up, therefore requiring only tightening by hand. 

Prior to starting the cutting or grinding application, discs need to be inspected for potential damage. The periphery of the disc should be intact, not chipped or frayed and flat, not warped. Never attempt to bend or twist the disc as the fibre reinforcing will be damaged, potentially forming a dangerous crack. 

Safe usage and operation pictograms are displayed on each disc label that should also present certain markings, like the OSA and EN Standard 12413 mark. These refer to the Organisation for Safety of Abrasives, and the European safety requirement Standards. Products carrying these marks indicate certified quality management with documented processes and internal testing facilities of the highest competence ensuring product safety for the end user.  

Safety pictograms on disc labels refer to required PPE during application, and material applications clearly advise the suitable material for the said abrasive.  

Taking the time to choose the best abrasive, and adhering to these tips, will ensure both a safe application, and the best results. 

Superflex is locally manufactured from only the best in raw materials, providing premium performance with the ultimate in product longevity. Available from Major retailers. 

Information courtesy of Grinding Techniques – +27 11 271 6400 | [email protected] | www.grindtech.com 

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