Current color case hardening

halfmoonclip said:

I've been wondering if the color case finish on many modern guns is really that, or an artificial coating applied by some other method?
In the greater scheme of things, it doesn't much matter. Old time color case was meant to reduce wear on otherwise rather mild steel parts. Modern steels are so much tougher that it isn't needed.
So, is modern color case purely cosmetic?
Thanks in advance,
Moon

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Is it purely cosmetic, and I am going to say yes. Pre 1900, everything is cheap, plain carbon steels. Nickel steels came in the 1890's and took time to get into firearm production. During the blackpowder era, cheap, unheat treated steels were just fine. I was on an email from Whitacre barrels, the blackpowder barrel maker was asked what materials he used, and I looked up the properties, and that stuff was weak. But adequate for muskets. Case hardening made the surface wear hardened, probably added something to the strength, but the layer is in the thousandths of an inch thick.

However, modern materials, I have a USFA 1873 SAA revolver with eye popping case hardening colors, and the frame is 4140. That material does not need case hardening. I asked Steve Earle why he used 8620 and not a more advanced material on his Fraser action



and the reason was, his customers wanted beautiful case colors and 8620 gave it to them.

Oh wow!



If case hardened surfaces are needed, there are salt baths and gas ovens that will do the trick, but won't give the pretty colors. Anyone can search and find pictures of gears with case hardened teeth. Don't look pretty like the expensive processes used on firearms.

https://gearsolutions.com/features/induction-gear-hardening-part-2/


And, firearm makers such as Ruger, are using steels that won't take a real case hardening color, so they have developed coatings that look good.

There are a lot of faux things out there, on the product, because customers expect it. Let me mention windows. Old time windows were made of panes because they could not make big sheets of glass. That was approximately when Henry VIII was king. You see a lot of modern, single sheet pane windows with plastic grids on them, to imitate the old look. The fake panes block the view, but have the look people want.

Chemical case coloring is a thing. I think we recently had a thread on line of shotguns with the upper end of models having been chemical case coloring. I have a friend who has an H&R (70s era, pre-brankruptcy) with a chemical case colored receiver. While chemical treatment can offer some very bright colors, I find them to border on or actually be garish. And they wear just like case hardening colors.

A good job of case hardened coloring (as in Slamfire’s post above) is very attractive.

Slamfire said:

And, firearm makers such as Ruger, are using steels that won't take a real case hardening color, so they have developed coatings that look good.

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Makes me wonder about the coloring Turnbull Restos offers:
https://www.turnbullrestoration.com...rently-unavailable,made-to-order&orderby=date

Slamfire said:

If case hardened surfaces are needed, there are salt baths and gas ovens that will do the trick, but won't give the pretty colors.

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I bet you could pack harden without colors if you used fine, uniform charcoal in the pack and quenched in clean, still water. I don't know why you would want to if you could have the work done by a more economic method.

Slamfire said:

the blackpowder barrel maker was asked what materials he used, and I looked up the properties, and that stuff was weak.

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Some years ago there was a debate over muzzleloader barrels said to be made with a particular grade of free machining leaded steel that turned out not strong enough even for black powder.

Jim Watson said:

I bet you could pack harden without colors if you used fine, uniform charcoal in the pack and quenched in clean, still water. I don't know why you would want to if you could have the work done by a more economic method.

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Since people want the pretty colors, I wonder how many would pay for case hardening without colors.


I was interested enough in traditional methods, and modern methods to create color case hardening, so I purchased the book

Colour Case Hardening of Firearms, principles and practices, Dr. John Seim.

I think of particular interest is the author's warning on page 21.

Older versus Newer Firearms.

Since the Second World War, firearms manufacturers have increasingly abandoned case hardend carbon steel to adopt stainless and other steel alloys which offer greater utility for a variety of specialized applications.

The list above (not provided here) summarized applications for a few types of specialized steel alloy. Of great significance, especially related to safety in its application, is that each alloy requires a particular and strict heat treatment process to produce a predictably useful item. This strictly controlled heat treatment process is not necessarily duplicable on an artisanal basis. Furthermore, manufacturers typically do not usually publicize specific details of which alloys that they employ so re treating a gun part involves a degree of “guesstimation.” Therefore re-heat treating some parts, such as bolts or receivers, can potentially lead to work-pieces which are excessively hard and brittle (risk of catastrophic failure under stress), or excessively soft and malleable (risk of failure as these parts leave original dimensional specifications).

Older firearms, particularly those manufactured in the nineteenth century, were more likely to have been made of hypoeutectiod carbon steels and tend to have more predictable properties than more modern pieces. Nevertheless, artisanal attempts to re treat any previously heat treated firearms component contains some risk, and it is certainly advisable to avoid re treating critical parts, whatever their age such as bolt rifle actions, gun bolts, handgun cylinders, slides or frames, and so forth, where a catastrophic part failure might damage a valuable firearm, or injure the shooter and those around.

To each his own, but to me this new fake coloring is a negative. Just a marketing ploy.

I don't even like case colors beyond a SAA receiver framed with a lot of blue. A Winchester action just looks blotchy.

Case will hold its color for more time if coated while warm with Bees wax.

Armorer 101 said:

Case will hold its color for more time if coated while warm with Bees wax.

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Real case hardening colors are delicate. I think manufacturers cover them with some clear coat paint. I know that is true for the faux colors.

Col. Harrumph said:

Makes me wonder about the coloring Turnbull Restos offers:
https://www.turnbullrestoration.com/product-category/the-showroom/turnbull-finished-firearms/?query_type_inventory-status=or&filter_inventory-status=current-inventory,currently-unavailable,made-to-order&orderby=date

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Turnbull is the BEST at what they do as far as color case hardening is concerned. Ruger certainly uses some of the most modern types of metal to investment cast and machine their firearms from, yet from what I've seen of the colors on several of the Ruger Mark IV pistol uppers and even a few of the Ruger #1 rifles, that they've done, the coloration doesn't pale one bit from all the other work done by them.