Chemicals that can alter/damage a case hardend finish?

[His lordship.]

Are there any chemicals like solvents or rubbing alcohol that can damage a case hardend finish like on the Colts and percussion gun lock plates?

I was removing some over drip of linseed oil on my pistol's lock plate last night with rubbing alchohol and was worried that the finish was damaged.  Fortunately I took several photos of the gun when I first bought it for insurance purposes and was able to pull up an image that showed no problem.  But still, it made me cautious of what may or may not be good for the protective finish.

[blhof]

Real case hardening is as chemical resistant as the metal, but many of the newer case hardened guns are a coating, as in paint or finish, which can be affected by harsh chemicals, when in doubt, try and check with the maker, most have a customer service and will inform you if anything is contraindicated.

[gcrank1]

And dont use 'nitro' type solvents which may contain ammonia. Some of them are harsh enough to take off the thin 'blue' and who knows what else.

[mcwoodduck]

Well,
Flitz, Never dull, and other polishes will take the color case off of a gun.
Don't ask how I know but the same flitz that will clean up any surface rust on a Colt SAA's barrel will polish the top strap to white in less time than it takes to tie your shoe.
Never dull will pull the blue off a gun.
Your standard gun cleaning stuff of Hoppies #9 and the like as well as the like are fine.
The spray stuff will melt Rubber grips like on a Colt SAA, Walther P-38,Sig P-2-- Series and will take a couple layers of varnish off of the wood grips.  Again Don't ask how I know.   

[Reverend Recoil]

Sweat from your hands can fade case colors.