What is this Brown & Sharpe tool?

[Mick56]

Picked this up at a sale, the tag they had on it says Caliper Gauge Measures Depth Metal Hole. At zero, the stem is extended to.75", when retracted it is at .25", so it has a range of 1/2". The back end looks like it should attach to something? Googled awhile but could not find this tool.

 

[d42jeep]

Maybe part of an inside micrometer.
-Don

 

[gorilla]

I'm not sure of the proper name for that but looking at the label on a brand new one it's called a micro-controle. It's not a measuring device per say but a micrometer head used to control motion on some unknown device. Sort on a mini version of a leadscrew on a lathe.

 

[Ecosta777]

It's a micrometer head, but it's missing the ratchet thimble. You can buy them for making custom measuring tools, stops, etc...

https://www.mscdirect.com/product/details/06236137

 

[Corndoggeh]

Agreed with others, you use that on a arm/jig/anything that needs micrometer adjustments. For example Ive used them on arms that carry sample pucks in vacuum chambers. Micrometer adjustments are critical to aligning multiple arms together to transfer a puck through long chambers.

 

[RTM]

Could also be part of a depth micrometer, on top of everything mentioned above. any other numbers on it?

https://www.amazon.com/dp/B003U9W0H4/?tag=atomicindus08-20

 

[ganymede]

As said above, micrometer head. Probably model 290 or 291.
Chrome plated means 1950+