Made a quick test video about angle grinder diamond metal blade.

Thanks for the reply, I would imagine using a diamond cutoff tool it would get hot.

We need to be sure that we are talking about the same kind of wheels. This is what I am talking about for cutting steel. https://www.ctemag.com/products/leno...-cutoff-wheels It is diamond, according to this information. The grit is bonded to the rim, it is very course.

I also have a 4 1/2" diamond blade that the rim is so smooth it will not cut you if you touch it. It cuts brick, concrete, tile, etc very easily. I typically use it wet, but have used it dry if I have to. I would never use it for cutting steel, I have never tried steel with this one, but I know it would be very slow and get very hot.