How To Zero An Old Brown & Sharpe Micrometer?

[JPMacG]

I picked up a very old Brown & Sharpe Model 48 1-2 inch micrometer for a price that I could not pass up. It is in decent condition but I don't understand how adjust (zero set) the reading.

The barrel and frame appear to be one solid part - the barrel cannot be rotated and there is no hole on the barrel for a wrench. I think there is a sleeve within the barrel and the spindle screws into the sleeve. There are two compression nuts - labeled A and B on the attached photos. I think the outer compression nut (B) is used to adjust for thread wear. I don't know what the inner compression nut (A) does, but I suspect it is used to make zero adjustments. I removed the nuts and tried to remove the sleeve but would not budge.

Can anyone explain how to adjust this thing? I'm perplexed.

 

[francist]

My old B&S has a small screw that allows the fixed anvil to be adjusted. Has nothing to do with the barrel end of the mic.

-frank

 

[JPMacG]

I have seen some B&S mics like that. There is no screw on the fixed anvil on this one. Thanks though.

 

[JPMacG]

Got it. The trick is to remove the ratchet cap from the knurled barrel, then the barrel can slip on the spindle. The ratchet cap locks down the barrel. One of our excellent HM members sent me a PM and told me how. I don''t want to disclose his identity without his permission. But thank you!!!