Fire Blue Parts

[PalmTree2]

Hi Guys,

Does anyone know when about Mauser stopped doing the Fire Blue on some Luger small parts, like the toggle pins? Some call it fire blue, some Peacock Blue.

1936?

Thanks,
Mitch

[MFC]

I believe it was at the same time they transitioned from rust blue with straw parts to all salt blue, in early 1937.

[John Sabato]

The correct terminology is strawed, not fire blued. Different process with different results than strawed. Strawing results in gold type coloring. Fire bluing has been used on some front sights, and grip screws I have seen, but I have never seen major components fire blued.

[DonVoigt]

I believe I would call it "heat treatment" or "drawing" or "tempering".
The colors range from light yellow through red and blue to grey. It can be done for decoration but is more often the result of drawing hardened parts to render them less brittle.

Fire blueing is a commonly used mis-nomer, there is a "fire" blue , sometimes called carbon bluing or carbonia bluing; I believe Colt was "famous" for this very pretty but not very durable blue.

Here are the colors and temperatures required to achieve them on polished steel. These are not "my" charts but borrowed from other posts on these forums.

[alanint]

The toggle pins on early DWM are indeed "Fire Blued", versus "Strawed".

[ithacaartist]

Originally Posted by DonVoigt

I believe I would call it "heat treatment" or "drawing" or "tempering".
The colors range from light yellow through red and blue to grey. It can be done for decoration but is more often the result of drawing hardened parts to render them less brittle.

Fire blueing is a commonly used mis-nomer, there is a "fire" blue , sometimes called carbon bluing or carbonia bluing; I believe Colt was "famous" for this very pretty but not very durable blue.

Here are the colors and temperatures required to achieve them on polished steel. These are not "my" charts but borrowed from other posts on these forums.

I think Smith & Wesson also did the thin charcoal blue. My Llama mini 1911-styled pistols from the 40s also seem to have it. Thin, indeed!

Other than heating without the presence of as much oxygen, I'm not sure there's a difference between the carbon bluing and "fire bluing."

[Rick W.]

In my simple opinion, the early Lugers were as much a piece of art, as they were functional. Different concepts, times, and labor.

I always heard that the straw left vintage Lugers in mid 1937, but is only that, I can offer no document that says such. Must be out there, I hear the 37 straw timeframe a lot mentioned here.

One might surmise, and only that on my part, that the fire blue small Luger parts, was discontinued with the advent of hot blue, why not do all of them the same and get more pistols on line? Again just wondering and conjecture on my part.

The heat tempering/drawing tables show a number of colours. The home guy can do ok with the home cooking stove on a polished part as discussed here on this forum, but the big boys have controlled furnaces and a special controlled timing recipe. The home guy with the kitchen can get close with a bit of experimentation on methodology(heat control/time). Recipes could even be applicable to certain parts because of variables to get a common hue.

The heated parts are really not very durable, but to some quite beautiful on a vintage firearm.

I have seen a little of steel coloring with nitre salts. Brownells has them, used straight up, at temperatures for different colors.

I have a curiosity about the bluing of later firearms, charcoal blue; Colt, S&W etc, but never got into it. I would suspect parts are heated in a charcoal environment, perhaps in a metal container; kinda like case coloring; but not quite. Not even a novice here.

Green case coloring perhaps is gone with the schwinn, perhaps because of the hazardous materials. Old case coloring is a sight to behold to some of us.

A full regalia early Luger is indeed a pleasant sight. Sometimes I forget it was really a war weapon. I suspect some of that, and maybe just time/labor/$ caused the specialized coloring to go away.

Perhaps the Sturgess book references might shed some light on when all of that went away?

[CJS57]

My 1937 with straw parts also has fire blue on the toggle train pins. My 1937 all blue has none. I think that is the dividing line for military guns. Commercials may be different.

[DonVoigt]

The time that Mauser went to salt blue is well documented, in "The Mauser Parabellum" and else where, it was in the second half of 1937.

There are many serial number lists for 1937 luger pistols that will get one closer to the actual change over if one is interested enough to look for it.

Toggle pins on early("strawed") lugers were indeed heat blued- they were drawn/tempered to the temperature that left the pins blue.

There are lists/commentary in some of the books regarding the temperatures that various parts were drawn to.

[Rick W.]

I have always found "The Modern Gunsmith" by Howe to be a nice reference for practical applications. This book has the table as per the home one referenced earlier.

[ithacaartist]

It's 42 Mb and won't post to the forum, but you can download a copy of materials and processes here: https://docslide.com.br/download/lin...structions-pdf