What TPI does a micrometer use

[tim81]

Hi Guys.

What TPI does a micrometer use. I read somewhere it was 40TPI. I am asking as my brother now that we got the lathe wanted to see if he can do precise movement mimicking the micrometer. Also it does not look to costly or dangerous to try out.

Any help is appreciated

Tim

 

[RJSakowski]

Most micrometers travel .025"/revolution so 40 tpi it is.

 

[tim81]

So what diameter can I use to make one. Can I try to make 1inch diameter with 40TPI

 

[mmcmdl]

Why not buy a mic head if it would work ? But as far as your question , you can thread any size material 40tpi if you want to .

 

[RJSakowski]

My metric micrometer is .5mm/rev. and my digital caliper which is Asian in origin is also .5mm/rev.

 

[RJSakowski]

Another way to obtain precise movement is with a differential screw. It is possible to obtain quite fine feeds with relatively coarse threads. For example, a differential screw using 5/16-24 tpi and 1/2-20 tpi threads would provide a travel of .00833"/rev..

 

[tim81]

Why not buy a mic head if it would work ? But as far as your question , you can thread any size material 40tpi if you want to .

I don’t know they are for sale. My questions are silly I know. But I can learn the lathe without doing any damage and make something remotely useful.

 

[tim81]

Wow like this one you mean
Micrometer Head Measure Tool 0-13mm Flat Type Plain Thimble Silver +/-0.01mm Accuracy https://a.co/d/9P8vuxF

 

[tim81]

Looks cool

 

[tim81]

Another way to obtain precise movement is with a differential screw. It is possible to obtain quite fine feeds with relatively coarse threads. For example, a differential screw using 5/16-24 tpi and 1/2-20 tpi threads would provide a travel of .00833"/rev..

Super cool.