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 ?

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.
Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Life; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Ed Huntress wrote:
"DoN. Nichols" wrote in message
...
According to Ed Huntress :

[ ... ]

For my 1" mikes I have 0.5" and 1.0" gage blocks. I have a similar pair
for
my metrics, and I use the inch gage blocks to cross-check the metrics
with a
"betweens" kind of test, and vice versa.

It ain't a formal certification but it keeps your gages honest enough for
ordinary work. If I used Chinese gages, I'd definitely get a pair of the
blocks to go with them.
There is something to be said for having standards which will be
measured at 1/3 and 2/3 rotations of the micrometer thimble (.008" and
.016" are close enough), as well as those which will have the thimble at
zero.

That's the value of the metric gage blocks with the inch mike, and vice
versa. And you get some interesting stacks by combining the inch and metric
blocks, too.

This will show up a case where the anvil and spindle are lapped
at an angle and will read properly as long as the rotation of the
spindle is in full turns, but will introduce a bit of error at other
rotations. This is not too likely in most cases, but for testing a new
cheap micrometer, it is a good idea. Even better for this is a set of
quartz optical flats of these thicknesses and the proper illumination
which will show this up even at very tiny angles. Probably meaningless
for most hobby work, but if you really care, another thing to check.

Uh, yeah. I would like to have a set of optical flats and an illuminator for
them, too. Then again, I'd like to have complete sets of inch and metric
gage blocks, and a master set I send to NIST every couple of years. g

--
Ed Huntress



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