Non-hydrocarbon based instrument lubricants

[Mgt3]

TL;DR Summary

Question about lubricants not made from hydrocarbons

Are there any non-hydrocarbon based lubricants that can be used on instruments like micrometer threads? I know silicone grease exists, but it doesn't have the film strength to protect the metal. Are hydrocarbons the only game in town?

 

[phinds]

You really should learn to use Google. Search for "non hydrocarbon lubricant" and you'll get 981,000 results

 

[Baluncore]

What unusual forces are there on the micrometer screw ?
What materials are the screws made from ?
Why are non-hydrocarbon lubricants required ?
Graphite.
Molybdenum disulfide.
Lead dust is used to lubricate bearings in closed vacuum systems.

 

[Mgt3]

You really should learn to use Google. Search for "non hydrocarbon lubricant" and you'll get 981,000 results

I did, but I also came across the fact that many of these lubricants do not have adequate film strength for metal on metal contact. So I asked the question.

 

[phinds]

I did

Then why did you ask

Are hydrocarbons the only game in town?

If you had already answered you own question

 

[Mgt3]

Then why did you ask

If you had already answered you own question

You're not reading what I said, which was, "but I also came across the fact that many of these lubricants do not have adequate film strength for metal on metal contact." The question is, while there are other lubricants, the information I have come across said many of these lubricants are not good for metal-on-metal contact because of the lack of film strength. Hence, I am asking which if any of these other lubricants could protect a micrometer screw.

 

[Baluncore]

The question is, while there are other lubricants, the information I have come across said many of these lubricants are not good for metal-on-metal contact because of the lack of film strength.

That sounds like marketing to me. Where did you read it ?
Please provide us with a link or a reference.

There should be very little force on a micrometer screw thread.
The last thing you want is a thick lubrication film on the thread.
Read the manufacturers lubrication specifications.

 

[trainman2001]

Why is "non-hyrdrocarbon" critical here. Furthermore, I've never heard of anyone lubricating micrometer threads in the first place. I have a Starrett 1" mic that's at least 60 years old and requires no lubrication at all. Threads are ground and polished and have very little friction. I don't move it fast it enough to generate any wear.

 

[berkeman]

Search for "non hydrocarbon lubricant"

Gun oil doesn't have any hydrocarbons? I think mine does, but I'll have to check tonight...

 

[nsaspook]

If you have critical instrumentation lubrication needs I would recommend these types.
https://www.krytox.com/en/products

Do not mix perfluoropolyether based lubes with a hydrocarbon-based grease.

 

[Mgt3]

Why is "non-hyrdrocarbon" critical here. Furthermore, I've never heard of anyone lubricating micrometer threads in the first place. I have a Starrett 1" mic that's at least 60 years old and requires no lubrication at all. Threads are ground and polished and have very little friction. I don't move it fast it enough to generate any wear.

How does metal-on-metal not wear?

 

[Baluncore]

How does metal-on-metal not wear?

Selected dissimilar metals that do not oxidise, high quality finish, without a load.

 

[Baluncore]

The question is, while there are other lubricants, the information I have come across said many of these lubricants are not good for metal-on-metal contact because of the lack of film strength.

That sounds like marketing to me. Where did you read it ?
Please provide us with a link or a reference.

Tribology is a peer reviewed science, not marketing with misinformation.
@Mgt3 When are you going to provide the reference that claims hydrocarbon lubricants are not good for metal-on-metal contact ?

 

[Baluncore]

Summary:: Question about lubricants not made from hydrocarbons
Are hydrocarbons the only game in town?

Consider also hexagonal boron nitrite, BNh .
BNh is a good lubricant for high temperatures, oxygen atmospheres, space or vacuum systems, or where electrical insulation is important. BNh replaces graphite which is conductive and oxidises.
https://en.wikipedia.org/wiki/Boron_nitride#Hexagonal_BN

 

[Tom.G]

A tip learned the hard way:

edit: Added phosphoric acid, 2 places & a footnote. /edit

The local college was selling off surplus used equipment where I found a 1"-to-2" micrometer with the 1.000" calibration standard for Zero setting.

I cleaned it up with phosphoric acid and it was good... Then I applied some Silicone Grease to the threads. That is when I found that the Satin finish on the micrometer, the phosphoric acid, and Silicone Grease are NOT compatible!

It seems that the Satin finish, along with any oxide layer on the threads, were completely removed, leaving a virgin, and active, metal surface. After a few turns of the spindle the threads seized solid.

A rather discouraging way to learn something new.

p.s. In a later discussion with a chemist friend, he mentioned a half-remembered reaction between phosphoric acid and silicone grease.