Tube pin question?

Many tubes I've seen have what appear to be discolored/burnt pins. These have all been steel pins not gold plated ones. Was this caused during manufacturing? I imagine everything gets pretty hot when the glass was melted to create the vacuum. Concern or not a concern? Thanks!
Not a concern , your right this happens during manufacturing and many NOS tubes have bad Oxidation on pins , you can of course clean these up carefully.
Use a wire brush-gently, then apply contact cleaner before using.
Thanks for your responses! I'll gently clean and then forget about it.
Unless the pins are rusty, don't use anything but a contact cleaner(like DeoxIT) on them. The discoloration is from heat(not oxidation) and will not affect conductance. Scratching the pins, with any kind of abrasive, or metal bristles(outside of brass or copper), will encourage the oxidation of steel pins. Good stuff: ( or higher temp (
Got it, thanks.
Forgive me! My semantics get in my way at times. The blue/black on the steel pins is actually a type of magnetite, created by heat(and oxygen), during the manufacture of the tube(as previously mentioned). That's a very thin, stable and anti-corrosive layer. A thickness of about .072 micron results in light refraction(per Michael Faraday's observed, "Temper Colors") and the blue appearance. It actually protects the steel from the nefarious, unstable corrosion/oxidation we call, "rust."
Stay away from any contact enhancers that are not in spray form. Quite often they have base carrier that can migrate. This can cause real trouble with tubes!

DeOxit in spray form is as powerful as you would ever want!
Is this magnetite part of the vacuum seal between the glass and the pins?
If it is I understand how a strong contact enhancer could potentially cause problems.
I would imagine that a strong enough solution could possibly destroy the vacuum and thus the tube?

BTW: Thanks for your responses, I've found them helpful.
Probably the best thing to do is wipe the pins down a bit with a clean cotton cloth just to remove any potential oil or grease and call it a day.
The bond of the glass to the pins will disallow the entrance of a cleaner. Folks have been using DeoxiT for decades. Just be certain to use it sparingly and not to leave anything on the bottom of the tube's envelope, that might conduct electricity, or migrate along the top of the tube holder. Personally; I re-wipe everything with Q-Tips, after application/cleaning.