Micrometer

Post by **minor_hickup** » Mon Aug 14, 2006 6:31 pm

For my birthday last year I got a set of vernier calipers and a micrometer. The calipers are self explanatory and have been very useful. However I don't know how to use the micrometer! (which is unfortunately metric!!) It has a sort of ratchet to it and I can't seem to make consistent measurements with it, there are no instructions so If there is some procedure could someone please explain?

Post by **Kevin** » Mon Aug 14, 2006 6:56 pm

The ratchet is for fine adjustment after you have turned the knurled part and when you have reached the size being measured and should read the same every time what shape are you trying to measure a flat piece or a bar.
When you are holding it the easyest way is to hold it in one hand with your little finger crooked around the anvil so that you are using the ratchet with thumb and forefinger.

Post by **minor_hickup** » Mon Aug 14, 2006 7:14 pm

I'm trying to a measue the thickness of a bar of steel for non moggy related things each time the measurement changes by up to 0.2

Post by **paulhumphries** » Mon Aug 14, 2006 7:20 pm

Have a "play" with metric feeler gauges.
You will know what the feeler is so you can work backwards to find the same measurement on the micrometer.

Paul Humphries

Post by **Alec** » Mon Aug 14, 2006 7:50 pm

Hello MH,
is it round or flat bar, whichever, it could be that you are not keeping the micrometer so that the faces are flat to the bar. A variation of 0.2 mm is huge by micrometer standards, nearly 8 thou in real money, and you should be able to read to 1 thou quite easily.
The ratchet is deisgned to take the guess work out of how tight you screw it onto the job, giving a more consistent reading.
It is normally more accurate and easier to use than vernier calipers.

Alec

Post by **minor_hickup** » Mon Aug 14, 2006 8:29 pm

The bar is just a rectangular bar about 1" wide and 2' long. At least I know what the ratchet is for, I'll go and have a play.

Post by **minor_hickup** » Tue Aug 15, 2006 8:43 pm

Well my brothers had a look at it and it turns out it was not together properly, so with some tightening with a very odd looking spanner device its working perfectly. Thanks for your replies.

Post by **Kevin** » Wed Aug 16, 2006 8:18 am

So it was down to owner/user misuse then

and to overlook your inhouse expert as well, not that I would ever do such a thing (well not too often anyway)..................
At least you can now get the best out of it.