sharpening HSS and cobalt

Nope, Green wheels have a looser bond designed for grinding tungsten carbide. White (alox) pink or grey caborundum wheels will do the job on HSS and cobalt tool bits.

Bob

Many thanks Bob. Pete

No.

Green for carbide.

Cheers Trevor Jones

Or, these days, diamond wheels. The ones from Arc are dead cheap and work fine, at least on the limited use I have given mine so far.

David

A chap at work told me to use grey. Pete

for carbide - the ordinary grey wheels a cheap grinder comes with are much better for HSS/HSS-Co.

I haven't used a green-for-carbide wheel in maybe 30 years, but I didn't think they worked well then. Have they gotten any better since?

Diamond is of course great for carbide, and it's getting so cheap now that I can't see any point in using green wheels for anything at all.

Diamond isn't quite so great for HSS/HSS-Co though, it doesn't last - though if you only use it occasionally, and at slower speeds, it may be okay. But it's much slower than cheap grey for removing a lot of metal from HSS/HSSCo.

-- Peter Fairbrother

The ones from Arc are dead cheap and

On carbide, yes. On Steel, not a great plan if the steel reaches red heat.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller