"Ed Huntress" wrote in message
...
On Sat, 15 Jun 2013 12:53:04 -0400, "Jim Wilkins"
wrote:

I checked my SB again, with some light this time. g It is 90
degrees, not 92. Apparently the protractor was slipping as I
tightened
the nut.

--
Ed Huntress

It's not an easy measurement.

If you built small things for a living these could be justified:
http://www.starrett.com/metrology/me...ortBy=none/asc

I bought a new 14D from a local supplier for $10, long ago, and a
pristine used 453C set for $7.99. The second knob on the 453C tilts
the blade up to 7 degrees to measure the draft angle in a punch press
die.
jsw