Rehab old micrometers

[vanapplebomb]

I recently pick up a 1-12” micrometer set with standards for my everyday “I don’t really care” use, so that I could save wear and tear on my nice Brown and Sharp micrometer I use for precision work. They appear to be older, and the grease in them seems to have dried out and hardened. Very sticky. I decided I would take them all apart, clean them good, lube them up, and set calibration again.

my question is what grease would you use to lube the threads with? I am assuming you would want something thin, like an NLGI 00 grade grease. If anyone has suggestions, I am all ears.

 

[wayne55]

I'm usually wrong, but I would just use a very thin film of white lithium .

 

[RTM]

Starrett makes a real thin oil for their instruments, that's what I put on all mine.

Starrett Product Details

www.starrett.com

 

[seber]

If they tend to sit without use for long periods, silicone based oil will not gum up like petroleum based.

 

[Mas78]

Use Hoppes 9 gun oil.
It's mostly mineral oil.

 

[vanapplebomb]

Looks like I have a few option available to me. Thanks for steering me clear of grease and to a light oil.

 

[bob15]

Grease is bad as it will attract debris in time.

Here is the best stuff to use:

 

[larry_g]

Use Hoppes 9 gun oil.
It's mostly mineral oil.

I too use Hoppes #9 gun oil to clean all my old tool finds. If still sticky then the Starrett oil shown above, just a drop.

lg
no neat sig line

 

[d.mcfarland]

No grease, just oil. Pick your favorite! I usually use gun oil because of the rust prevention properties.

 

[vanapplebomb]

Well, I took them all apart and cleaned them. Gun oil is what I had on hand, so it is what I used to lube the threads and anvil. worked great!

I will have to adjust them slightly, but that shouldn’t be to hard now that everything is moving nice and smooth.

my only question is how accurate the standard bars are that came with them. There was no certificate in the box. I may set initial calibration with the standards, and then double check with a certified set of standards at my local machine shop... just to see where the standards I have are at in relation to a known good set. I don’t have a lot of faith in no-name standards with no certification.

 

[Shiftless]

Check against your Brown and Sharpe mike.

 

[Firebrick43]

I clean them with contact cleaner and use synthetic super lube oil as it doesn't gum up

 

[vanapplebomb]

Check against your Brown and Sharpe mike.

Unfortunetly, I only have B&S 1-3” micrometers and standards, so my new to me 4-12” micrometers and standards are still a mystery.

from what I am measuring, it looks like the 1-3” ones are good, when comparing to my B&S set.

I do notice that the 4-8” mystery standards don’t behave like the ends are ground perfectly parallel. They want to walk off center... that said, I still get consistent measurements on them.

The 9-12” mystery standards are radiused on the ends, which I like.

 

[californiaHank]

+1 on Starrett's 1620 'Tool and Instrument Oil'.

It's what goes on Starrett mikes and calipers at the factory.
You'll find lots of other uses for it - It's pure light mineral oil without added solvents or other **** (and it sells for a lot less than Mitutoyo's equivalent).

 

[macgee]

my only question is how accurate the standard bars are that came with them. There was no certificate in the box.

Thats a tough one, I come across a lot of these mic. sets and having to do what you just did. I probably have serviced 20+ or so mic.'s this spring. Really important to remove that grease as that sticky hard to turn thimble can wear out the very important threads, damaging them or bend them while trying to do so and then the thimble rubs on the sleeve. First thing before turning, I tend to shoot a bunch Tri-Flow (as much as I can patiently) between the sleeve and thimble and where the spindle comes out and then let it sit for a couple of days or more. That usually will always loosen them up and then you wont have to do that dreaded hard cranking on the thimble with a wrench, some thimbles are totally glued in, rock hard. You've already serviced them so info above is mute but hopefully others will find it useful.

In regards to included B&S standards, they're a **** shoot. This week I actually tried using older HSS 2" and 3" B&S and they were hard to use and were off 4 of 5 tries. The tips have a slight dome to them and like you experienced they like to walk giving you off measurements leaving you scratching your head. I have several round 1.000" B&S standards and four are off.
If you have a surface plate, try laying the micrometer flat, thimble off the edge to turn and try checking that way, you may need to shim the standard to be level with the anvils; this helps from keeping them from walking. If you have ledges on you plate, maybe clamp the Standard to keep from walking living you hands free to use mic.
I actually gave up with them and used a set of Mitutoyo's from another set but not before pulling out my good gage blocks which go up to 6" . Those worked well and agreed with the Mitutoyo's.

I have gotten Mic. set's and some of included standards are off, it's not uncommon but I'll also get set with beautiful carbide and very accurate standards. Long standards are hard to test, slightest angle throws them off which is easy to do

Your mic's are probably only .001" so as an example you can get away combining your 4" & 3" gage blocks to measure your 7" in the surface plate.....etc. I used my 6" & 4" for 10" mic

 

[vanapplebomb]

Both my old 1-3” B&S mics and these new to me mystery 1-12” mics are 0.0001”

So, in theory, the standards should be a factor of 4x more accurate than the mic, or +/- 0.000025” correct?

My B&S flat ground standards behave vary nicely, and seat well like they are ground parallel. It is the “flat ground” mystery standards that behave like the flats are not parallel because they want to walk off center when tightening the anvil, even though they measure consistent each time I use them. Maybe it isn’t any an issue because it seems consistent any way it lands?

The long radiused mystery standards seat nice and don’t walk about. I actually kind of like the radiused ones. I have used other radiused ones in the past and liked them as well.

 

[macgee]

Sounds like your all set

 

[vanapplebomb]

Yeah, for now, I will call it good. How bad could it be?... wait, don’t answer that.

Hey, for my every day non fussy use, they should be more than adequate.