"Ed Huntress" wrote in message
...

It's not a SB 10L. All three Vs appear to be around 92 degrees,
just
checking it quickly.

I thought so too until I put one of my steel protractors on them a
little while ago. I couldn't fit my vernier protractor in there, so
I
had to use a sliding-leg protractor with no degree marks. It
definitely looked sharper than 90 degrees.

Ed Huntress

The square end of a steel rule is a nearly light-tight fit in the
internal vee of my SB 10L micrometer stop.
jsw