Case Hardened Receivcer

[BigBoy1]

I have encounterd a pistol, manufactured circa. 1935, whose reveiver has been case hardened. It has the brown/purple color. My questions are: Would the case hardening process affect any tempering/hardening that was done to the receiver? I have seen blackpowder guns that have had case hardening done to them but would it affect the srength of a smokeless propellant firearm? Can the case hardening be removed and the receiver be reblued?

Some where in its life time, the case hardening was done to the receiver. I don't have any idea why it would have been done. I have seen other identical guns that had the blued finish. Appreciate any thought or comments.

[JCHannum]

Bluing, as it fades, can get a purple brown cast to it, that might be what you are seeing. It is also possible the gun was case hardened at some point for whatever reason.

Color case hardening is a heat treating process, it would remove any original hardness and impart a different hardness. It might or might not affect the receiver.

Case hardening in itself is not necessarily only confined to black powder firearms, it is commonly used in smokeless powder firearms as well. Smith & Wesson has recently introduced a nostalgia line of revolvers with CCH frames.

A photo of the gun might help answer your question.

[Dutch51]

I have encounterd a pistol, manufactured circa. 1935, whose reveiver has been case hardened. It has the brown/purple color. My questions are: Would the case hardening process affect any tempering/hardening that was done to the receiver? I have seen blackpowder guns that have had case hardening done to them but would it affect the srength of a smokeless propellant firearm? Can the case hardening be removed and the receiver be reblued?

Some where in its life time, the case hardening was done to the receiver. I don't have any idea why it would have been done. I have seen other identical guns that had the blued finish. Appreciate any thought or comments.

Make & model of handgun?

How did you determine the receiver was case hardened? The color of the part has nothing to do with much of anything.

Your question: Would the case hardening process affect any tempering/hardening that was done to the receiver?

I don't know how to say this without sounding like I'm flaming you but case hardening and tempering/hardening, as you call it, are not done to the same item. Its either one or the other. There's absolutely nothing to gain nor do I think you can actually do both to one piece of steel as the case hardening temperature would destroy any hardening/tempering done.

Handgun receivers... and I have to wonder which part of the gun you're referring to, if an autoloader the frame or slide, or a revolver? Your terminology says you're not real familiar with these terms... or you're not real familiar with them in English.

I'm going to assume your thoughts on the brown/purple color are leading you to think the part in question has been case hardened. This would be an incorrect assumption.

Bluing turns brown with age. We would call that "patina". This discoloring of the blue would not be uniform over the whole surface. It may affect some areas more than others.

Some bluing of a purple hue is the result of bluing temperature or some other methodology deviation in the process. A purple hue does not indicate case hardening.

Dutch
http://dutchman.rebooty.com
Swedish Mausers 1894 & 1896
Swedish rolling blocks

[J. Randall]

Bill, if your pistol originally had a high enough carbon content that it could be heat treated, and then it was color case hardened, yes you could have a problem. It is possible that when it was quenched it left the metal brittle throughout, instead of just having a hard case with a softer core as usually happens with low carbon steels that are ideal for color case hardening.
James

[JCHannum]

Without either a photo or make and model of the gun, it is impossible to make any kind of statement as to whether or not it has been casehardened. As I mentioned, I would suspect the purple/brown is the original blueing with typical aging.

Color casehardening typically is blue with reds, yellows and other colors mottled through it depending on the process used. It fades to a grey color with age. Plain casehardening is a uniform grey.

[BigBoy1]

I have decided against buying the gun so it is now a moot point. I'll let someone else worry about its finishing. I was considering buying it because its serial number was only 2 digits from the one I have. But the price and the "funny" finish has put me off on getting it.

[44-henry]

Make & model of handgun?

How did you determine the receiver was case hardened? The color of the part has nothing to do with much of anything.

Your question: Would the case hardening process affect any tempering/hardening that was done to the receiver?

I don't know how to say this without sounding like I'm flaming you but case hardening and tempering/hardening, as you call it, are not done to the same item. Its either one or the other. There's absolutely nothing to gain nor do I think you can actually do both to one piece of steel as the case hardening temperature would destroy any hardening/tempering done.

Handgun receivers... and I have to wonder which part of the gun you're referring to, if an autoloader the frame or slide, or a revolver? Your terminology says you're not real familiar with these terms... or you're not real familiar with them in English.

I'm going to assume your thoughts on the brown/purple color are leading you to think the part in question has been case hardened. This would be an incorrect assumption.

Bluing turns brown with age. We would call that "patina". This discoloring of the blue would not be uniform over the whole surface. It may affect some areas more than others.

Some bluing of a purple hue is the result of bluing temperature or some other methodology deviation in the process. A purple hue does not indicate case hardening.

Dutch
http://dutchman.rebooty.com
Swedish Mausers 1894 & 1896
Swedish rolling blocks

I do disagree with you on the tempering part of your statement as it is in fact possible, and even common, to temper parts that have been casehardened. In the case of bone and charcoal color case hardening drawing the parts at 400-450 degrees for an hour after the quench improves the colors and also has the benefits of drawing back some of the hardness making it less likely that you will have an extremely brittle part if it so happens that the carbon penetrated completely through thinner sections of the part or, god forbid, the part happened to be made from a high carbon steel to begin with.

In the end really all you are doing in the casehardending process is adding carbon to a piece of steel that had too little to begin with to be adequately hardened. Generally you are only doing this to the surface, but at that surface you have created a layer of high carbon steel that will respond the same as any other high carbon steel would. Early steel makers actually used the casehardening process to make some of the early blister steels.

All in all I would say that if you have any doubts about what has been done to this gun, and judging by the terminology that you are using you do, I think you made a wise decision to turn it down.

Alex Johnson

[gwilson]

Some steels turn purple when you are trying to blue them . I THINK I saw a refinished Ruger do that,but it's been 40 years!! Gun was blue,frame was purple. I knew the guy who reblued it,and it was in his shop.

[38_Cal]

With Ruger products, it's been known to happen fresh from the factory. When I worked at a gun shop in Oakland, CA, we would regularly (4 to 5%) pull brand new Ruger revolvers from the box with the frames a red color. With cast steels, if too much silicon is used in the alloy, it may never color properly with hot caustic salts. The "red" "purple" color can also happen on case hardened steels and irons, and occasionally on springs.

David Kaiser
Montezuma, IA