Micrometer mystery

[BazyleParticipant @bazyle]

Couple of these micrometer heads came up at the club auction last night. Rotating the spindle moves the ‘arm’ out of the end of the thick round body. Is it a recognised standard tool? Maybe just oart of some forgotten machine.

[mark costello 1Participant @markcostello1]

They would be a good starting piece for a micrometer stop on various machinery.

[Robert Atkinson 2Participant @robertatkinson2]

They look like custom items. Something like measuring the depth of a hole (that the body will slip into) referenced to a surface the length of the arm away. Not sure what though. Could be something hydraulic like a pump or valve body.

[DC31kParticipant @dc31k]

A micrometer needs two reference surfaces – on a standard tool they are the fixed and the moving anvil.

What is the second reference surface on the one you have? My guess is the cylindrical face of the part in which the arm slides.

There appears to be a domed item on the end of the graduated barrel – is that relevant, or is it just a screw?

When the dial is set to zero, what is the relationship (measurement) between the face of the arm and the face of the cylinder? When the dial is set to 1″ what is the relationship? Are the scales zero left or zero right?

[BazyleParticipant @bazyle]

I’m afraid I can’t give any more info as someone else bought them! Lots of potential to build them into something though so we will see what he does with them

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