Posted By Bob Youel

My advice is to put the manufacturers recommended disc onto the recommended tool -crossing over should be a 'no-no'

It may appear wastefull in some situations to an accountant etc but they do not have to use the tool nor suffer the accident

I am sure that your insurers would offer the same advice

Posted By John Lawlor
Hi Seamus

I have just gone to check our grinders 9" and 4.5" the ratings on the discs are 6600 rpm for the 9" and 13500 rpm for the 4.5" but also the center hole for mounting the discs are different sizes the 9" has a 22mm hole and the 4.5" has a 10 mm hole id reckon mounting a 9" inch disc to a 4.5" grinder would be extremely dangerous because for sure you would get chatter as it would be very difficult to center the disc on the spigot and the disc would break up

and I have asked our welders if they would do this and they concur that it would not be a good idea for the above reason and these guys use these grinders every day