Dave Baker wrote:

That's definitely the best way I agree, not that I have any and have to
make do with the mike for setting.

Just a warning for using the mike.
You will get to small readings (about 1..2/100 mm) if you don't put a
load on the mikes anvil (pressing slightly outwards; 10 N force is about
right to make the mike's ratchet work) when adjusting it. Don't forget
to lock the mike's anvil under load.

I once cross checked a inner mike, a ring gauge and a mike and always
got that error, so I doubted the ring gauge. But the ring gauge was
only 0.5/1000 mm below size (I took it for calibration). The error came
from the minor blacklash of the outer mike. Remember that mikes do have
a ratchet, some backlash and need a defined load to be accurate.

Jo blocks and a special fixture or ring gauges are the only reliable way
to set bore gauges. I do have only one ring gauge and use the mike.


Nick
--
Never use force, just go and get a bigger hammer.