Instead of "piggyback", put them blade-to-blade on a known gauge plate, then
look for light. If they're both good, and your gauge plate is flat, you'll
get a blackout join. If not, borrow a known good one, and figure out which
(or both) are worn or bent. (Maybe instead of borrow, you could haul yours
down to a shop that has the facilities, and ask as a favor to check them
out)



LLoyd

"Ben Jackson" wrote in message
...
Ok, this is a stupid question, but are the inside faces of a machinists
square supposed to be square, or only the outside faces? Or, put another
way, are the blade and base faces both parallel?

I've got the old "never take two clocks to sea" problem -- I've got two
squares and I piggyback them and I can see light between the blades.
So now I don't know which one is off...