Winston
> All have been good and even, but I haven't gotten every type. McMaster has a 0.5 micron rouge colored bar and a green bar that's 1 micron. I have both coming today to see how fine they are. If the green bar is actually 1 micron, it will be finer than the microfine compound sold to woodworkers (used to be sold as 0.5 microns, but the manufacturer says particles up to 6 are present in it. It works well, but no great reason to pay $11-$14 for 6 ounces when a 2 1/2 or 3 pound bar from industrial or buffing suppliers is more or less the same price.

That must be the same green bar I got from from McMaster. I can't say how fine the particles actually are though. I wouldn't have expected 1 micron scratches to be as easily visible as the scratches I actually saw from the green compound (using the stick directly, without the buffing wheel), but it's hard to say for sure how deep those scratches were. And maybe there were clumps of abrasives, making for deeper scratches? At any rate, the scratches with the same compound on a buffing wheel were much smaller.

I did a little Googling and poking around on the Osborn/JacksonLea web site, and what do you know, the MSDS sheets say that the green (supposedly chrome oxide) and red (supposedly iron oxide) compounds have a lot of aluminum oxide, like 10x as much as the stuff they're advertised as.

Green: https://www.osborn.com/media/msds/pdf/47012.PDF
Red: https://www.osborn.com/media/msds/pdf/47013.PDF