# Whar are these micrometers used for



## Ken_Shea (May 7, 2013)

*What are these micrometers used for*

Look like a conventional 0-1" micrometer but both contact surfaces come to a point.
While not an exhaustive search a search was made with out any real answers.
The closest was a crimp height micrometer but the included angle of the twp points were higher.

Thanks


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## onecut jimmy (May 7, 2013)

Ken_Shea said:


> Look like a conventional 0-1" micrometer but both contact surfaces come to a point.
> While not an exhaustive search a search was made with out any real answers.
> The closest was a crimp height micrometer but the included angle of the twp points were higher.
> 
> Thanks



Sounds like you have a thread mic.


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## Ken_Shea (May 7, 2013)

Thread mic's have a male and female contact that I've seen.

EDIT:
You could be right, just tried it and the angle is 60°
But measurement would sure be tricky and prone to error it seems.


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## Grumpy Gator (May 7, 2013)

A picture and brand name ,model number would go a long way in the answer to your question.



They come in all shapes and sizes for a specific app.
***********Just Saying****************************G*********:bash:


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## Ken_Shea (May 7, 2013)

Your pictures didn't help much.

Just did not see any need to take time to take and post a picture when everyone here has seen a 0-1" micrometer and stating that both contact surfaces come to a point seem clear enough, guess some people need a picture drawn, just saying...........

There is no model number on it but the manufacturer is J.T. Slocomb

Ken


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## pdentrem (May 7, 2013)

Point Micrometer.

We use them to get into tight areas. Like between the stamped edge so that we do not measure the burr caused by the stamping action.

http://ecatalog.mitutoyo.com/Point-Micrometers-Series-342-142-112-C1116.aspx

Pierre


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## Bill Gruby (May 7, 2013)

Sounds like it's for measuring sheet stock. I have one. I'll dig mine out and let you compare.

 "Billy G"


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## Ken_Shea (May 7, 2013)

pdentrem said:


> Point Micrometer.
> 
> We use them together into tight areas. Like between the stamped edge so that we do not measure the burr caused by the stamping action.
> 
> ...



Pierre,
Those are very similar but with a sharper angle.


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## kd4gij (May 7, 2013)

*Mitutoyo - Point Micrometers - Series 112*





*Details*


*Features:*
IP65 water/dust protection (Series 342)
Pointed spindle and anvil for measuring the web thickness of drills, small grooves, keyways, and other hard-to-reach dimensions.
15 degree and 30 degree measuring points are available.
The measuring points (carbide-tipped) have approximately 0.3mm/.012" radius.
With Ratchet Stop for constant force.
With SPC output (Series 342).
With digial counter (Series 142).
With a standard bar except 0-25mm and 0-1" model.
Supplied in fitted plastic case.
*Function:*
Origin-set, Zero-setting, Data hold, inch/mm conversion(inch/mm models)
Alarm: Low voltage, counting value composition error"


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## Tony Wells (May 7, 2013)

A couple of things about using a 60° angle point mic for threads is that you need to know that you have a root radius or flat in a thread, and the helix angle of the thread is in play, and the thread angle is symmetrical about a constructed line perpendicular to the thread axis, so the points cannot contact the flanks of the threads equally. They may be of some use in measuring threads in a comparator method, where you have a known good thread to measure and "compare" the readings. But they are more designed simply for measuring things in narrow spaces, like splines, etc.

True thread micrometers have a vee anvil, not a point. I have a set of thread triangles that sub for a thread mic, in a way. The difference is that they do slide sideways and compensate for the thread helix. Still, the other factors I mentioned enter the realistic use.


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## Ken_Shea (May 7, 2013)

*kd4gij* 	 ,
Those are like Pierre linked to and are close but much pointier.

These have a 60° angle and also have a small radius at the point, onecut jimmy was correct in his remark.

Thanks all, mystery solved it seems )

Ken


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