Tube pin question?

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: (http://store.caig.com/s.nl/sc.2/category.188/.f) or higher temp (http://store.caig.com/s.nl/sc.2/category.279/.f)

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."