On Sunday, July 28, 2019 at 2:02:55 PM UTC-7, Bob La Londe wrote:
I can just grab a piece of tool steel and go stand in front of the
grinder for a while, but I was wondering if there is a simple elegant,
not over priced tool to do the job. Ring groove will likely be 1.1"
give or take.

If it were for a big bore cylinder, I'd consider a slitting saw blade with
suitable width, even if it were broken (just choose a good tooth, and take aim).
Hand-sharpening a square cutter for a composite boring bar could
work, but it's not something where I can really see the cut, so if I sharpen
it wrong... how would I ever be able to correct it?