I have a 4,5 and 9 in angle grinders and recently had trouble using the 4in doing some cutting jobs. The discs shattered and broke pretty easy. The job was just cutting some aluminium posts.

After researching the web and reading about some of my bad habits which I wasn't aware of, I thought this the place to ask of those in the trade.

What disc for what job and how to apply disc size and wattage of the grinder to a particular job.

Also read that the 9in grinders have been banned on worksites!