# Starrett   103-C Adjustment



## Chucketn (Aug 3, 2013)

I inherited A Starrett 103-C 0-1” micrometer from my latefather. It came to me without a case, instructions, or calibration wrench. Doesanyone out there have one of these mics that could provide the instructions asto the calibration? I have a gage block set coming in a few days, and will beable to check its accuracy, but would like to be able to adjust it ifnecessary. 
Chuck


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## Codered741 (Aug 3, 2013)

There are two different things to take into account when calibrating a mic.  First is zero, which is rather easy.  Second is accuracy.  That is not very hard to determine, especially with gauge blocks, but not easy to adjust.  

First.  Setting zero, especially on a 0-1" mic is as simple as running it closed, and adjusting the barrel with the included, but often misplaced, spanner wrench.  With larger mics, a standard is used to make the anvil contact the spindle.  Make sure that both the anvil and spindle are perfectly clean, and free of any debris, even lint!

Second.  Checking accuracy is easy.  Take a gauge block and measure it.  If the block and the mic read the same, you are golden.  Do this with a couple of different measurements, properly wringing the blocks to ensure accuracy, to verify accuracy along the entire stroke of the mic.  If you do find discrepancies, Unfortunately, I do not believe that it is correctable, without replacing parts.  This usually occurs due to wear, often at the small end of the range.  Maybe someone else knows if they can be adjusted.  

-Cody


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## Chucketn (Aug 4, 2013)

My mistake, the mic is a Starrett #203-C, not #103-C.

The dia of the barrel is .476” and the pin hole is a snugfit for a #52 drill shank. The Starrett measures the drill shank at .0625”
Pics here:  http://s571.photobucket.com/user/chucketn/library/Starrett%20203-C%20mic

Chuck


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## awander (Aug 4, 2013)

It's pretty simple to adjust the zero-clean the anvil and spindle faces, lightly run them together, apply the lock, and use the spanner wrench to rotate the sleeve so it reads zero.

http://www.google.com/imgres?imgurl...3b-UezcCJev4AOGvoCQDQ&ved=0CDEQ9QEwAA&dur=275


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## Chucketn (Aug 4, 2013)

I neglected to say, I don't think the mic needs calibration, just want to be able to do so if/when needed. The mic does in fact read 0 when cleaned and closed.
Does anyone have a Starrett pin spanner they'd part with that would fit this mic? I e-mailed Starrett today, but naturally no response yet.

Chuck


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## awander (Aug 11, 2013)

Chuck:

Did you get your spanner? I have some extras and I'll send you one if you let me know your address.


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## Chucketn (Aug 11, 2013)

awander said:


> Chuck:
> 
> Did you get your spanner? I have some extras and I'll send you one if you let me know your address.



Andy, I did get a Starrett Spanner, and it does fit my Mic. But thanks for the offer.

Chuck


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