VINTAGE BROWN & SHARPE USA NO 25 MICROMETER

[Scott S]

I have what appears to be an extremely rare vintage micrometer made by Brown & Sharpe in early 1900s. It is a No.25 Direct Reading Mechanical Digital Micrometer with a very unique readout system. I hope someone will have more information about this unit. I have only found 1 photo of one, and that was from about 10 years ago.
Thanks
Scott

 

[L Vanice]

Old tools are best discussed in the antique section. My 1922 B&S catalog has the No. 26 digital mike, but not the 25.

Odd Micrometer, anybody seen one like this?

I dont think i have ever seen a micrometer like this one: RARE Central Tools 1 4" Micrometer with Easy Read Numbers | eBay Has numbers that rotate in the thimble. My question is, has any other manufacturer made a micrometer similar to this one? I cant think of any, but maybe someone else has...

www.practicalmachinist.com

Brown & Sharpe no 25 Micrometer??

Saw a B&S #25 Micrometer on e-bay, looks like they go for relatively high prices; does anyone here know about these? Are they super rare? What’s the deal ? http://www.ebay.com/itm/Antique-Brow...item27d1eb1172 http://www.ebay.com/itm/Brown-Sharpe...p2047675.l2557 Thanks Mike

www.practicalmachinist.com

Larry

 

[Scott S]

Thanks Larry, every bit of information helps to fill in the gaps in what I know. The 1922 B&S catalog helps confirm that it was discontinued before that, making it over 100 years old.
Scott

 

[Scott S]

For anybody interested these are some photos of this unit.

 

[ncjeeper]

Interesting mic.

 

[Aejgx6]

I'd like to see the guts!

 

[EPAIII]

That is cool! A 100+ yo digital micrometer.

WOW!

 

[Asquith]

I have two, both broken.

Ingenious design, beautifully made, hopelessly delicate.

There should be a key which slides in the keyway just visible in the alloy sleeve, with a peg on one end which engages with a cam groove. I think the problem is that they wanted to minimise the diameter of the alloy sleeve, with the result that the key/cam was far too thin and flimsy to survive.

 

[Scott S]

I'd like to see the guts!

If you haven't already seen it, Asquith has posted a photo of the internals.

 

[Scott S]

View attachment 445923

I have two, both broken.

Ingenious design, beautifully made, hopelessly delicate.

There should be a key which slides in the keyway just visible in the alloy sleeve, with a peg on one end which engages with a cam groove. I think the problem is that they wanted to minimise the diameter of the alloy sleeve, with the result that the key/cam was far too thin and flimsy to survive.

Thank you for your post and photo of the internal parts. It makes it all the more amazing that the one I have is fully functional.

 

[SkeeterFX21]

I have what appears to be an extremely rare vintage micrometer made by Brown & Sharpe in early 1900s. It is a No.25 Direct Reading Mechanical Digital Micrometer with a very unique readout system. I hope someone will have more information about this unit. I have only found 1 photo of one, and that was from about 10 years ago.
Thanks
Scott

I also have a #25 but is currently not functioning correctly. There is a small pin with string attached. Not sure where it goes. I inherited this, and a depth gauge also from an old inventor named R. Royal. I also would be interested in vintage and possibly how to repair this.

 

[Asquith]

Skeeter,

That's interesting. I haven't seen one of those little keys. They were missing from both my examples.

I figured out what was needed, and made one as an experiment out of mild steel. I filed it to shape, to slide in the keyway in the aluminium sleeve and to engage in the cam slot and notches (features visible in my photo, post #8). In fact I made two - I dropped the first one, and gave up trying to find it!

I thought it was a reasonable fit, but it was too weak (and probably inadequate, fit-wise) and immediately got chewed up.

Perhaps the previous owner of yours bought a new key from B&S, but then decided not to bother.

 

[honrick]

As someone who has also struggled with broken No. 25's, I appreciate the excellent photos supplied by Asquith of the innards of this micrometer. And thanks to SkeeterFX21 for the photo of the pin. If possible, can SkeeterFX21 provide a couple of close up photos of the pin that accompanies his example? Thanks.

 

[rivett608]

I have some that work and some that don't. I have taken them apart and made the missing or broken parts but that was years ago and I don't remember any of the details. Guess I need to fix some of the broken ones.

 

[SkeeterFX21]

As someone who has also struggled with broken No. 25's, I appreciate the excellent photos supplied by Asquith of the innards of this micrometer. And thanks to SkeeterFX21 for the photo of the pin. If possible, can SkeeterFX21 provide a couple of close up photos of the pin that accompanies his example? Thanks.

 

[SkeeterFX21]

OAL .5010”, thickness.0165”, thickness @ detent .0395”
Hope this helps still looking to figure out how all this goes together.

 

[honrick]

Thanks SkeeterFX21 for the pictures and the dimensions. Much appreciated.