"Martin H. Eastburn" wrote in message
...
Unless someone has been trained or studied a manual, the improper use
of blocks can give wide and inconsistent errors.

e.g. - can you stack steel and ceramic together and have the stack
stay together holding only the top block and letting the rest hang down ?

Yes. There's a photo of ten Mitutoyo gage blocks in a stack, mixed steel and
zirconia ceramic, held by the top one, in an old article in Modern Machine
Shop. It's my hand holding the stack.


The surface must be clean. The blocks not just placed, but twisted
together.

Quality knowledgeable people know all about that and then some.

The shop machinist has to know as well.

If you stack say, three blocks, and they're improperly wrung, the total
error of that stack might be 0.0001" or 0.0002". That's plenty close enough
for the kind of checking we're talking about. The average hobbyist is going
to have trouble reading absolute tenths, anyway, due to a host of factors.

However, if you're working in the sub-tenths range of accuracy, you need
very good technique, as you say. Just handling gage blocks with bare hands
can defeat you in that range.

--
Ed Huntress