This is the profile I ground from M2 bar stock for shear scraping the
inside of hollow forms freehand- the cutouts are there because the M2
is used punch tooling, and the piece I used started life as a square
punch- if I was starting from round stock like drill rod, there would
be no reason for it to be there.

Works really well, and leaves a surface that does not require sanding.
The tool is used by mounting the tool steel into the end of a 3-4'
pipe, and holding it near the center and at the end while bracing it
against the midsection and scraping the inside with a smooth motion by
moving at the waist and keeping your arms steady. No toolrest (I
tried it with the toolrest at first, and it didn't work nearly as
well- this is a freehand tool, to be sure.)

I had thought that the side angle was relieved, but upon inspection,
it turns out I ground it kicked out rather than angled in. It wasn't
what I had intended to do, but it works well, so I'm not about to
complain- it could be that that is the reason it works well freehand.