Annealing Brass

[ky_man]

I am wondering if I will need to anneal the brass triggerguard on my pistol project before I bend it into shape. I've heard that brass is annealed analogous to hardening steel, but how hot to get it? I don't want it to oxidize and crumble apart.

I've heard that brass work hardens, so if I cold bend it without annealing it first, will it be harder to re-bend it a second time? Looks like I will have to bend the triggerguard in quite a few places to make it fit.

 

[paulvallandigham]

Rebending is what breaks brass castings. Brass is softened the opposite of the way steel is done.

To Anneal brass, heat it red hot( Turn the lights down so you can see the brass turn red!) then quench it in water quickly. That is how it is annealed. Do this before bending, and don't bend brass too far one way, and expect to bend it back, without first annealing the brass part again. Bending will work harden the area that is bent, and too much bending will break it. I can't think of a reason to harden brass after you have formed the trigger guard, or buttplate, or thimbles, so it is not done. However, to harden brass, you heat it back up red hot, and then let it cool slowly. The slower the cooling, the harder it becomes.

The problem with hardening brass that has been bent, or worked into some shape is that when you heat it red hot, it becomes so soft, and maleable, it might change its shape during the hardening process and you won't notice it until you have repolished the piece, and are now preparing to mount it on the completed gun! One of the reason that castings are used for brass parts is that you can get them to the correct angles, and sizes WITHOUT bending them, and then re-hardening the pieces.

 

[Blizzard of '93]

that is correct Pazul, to anneal brass it is quenched from heat suddenly, ice salt water is best.

 

[Vaino]

As said previously, dim the lights and heat 'til red....I don't quench in water and my brass always anneals. Heating brass and letting it cool slowly is exactly how I anneal brass and it certainly won't harden this way. Quenching the red hot TG in water could cause cracks, especially if there are voids. I usually cold bend unannealed TGs with my fingers, spreading out the force to avoid cracking. If extensive, severe bending is req'd, perhaps a different TG should be purchased that fits better. I have never had to bend a TG a whole lot, just to bring the front and rear finials parallel to the fore end and wrist.....Fred

 

[Mike Brooks]

However, to harden brass, you heat it back up red hot, and then let it cool slowly. The slower the cooling, the harder it becomes.

That is incorrect.

 

[Roy]

Just always taking chances bending cast parts regardless is my experience. Here lately I have been lucky.

 

[TANSTAAFL]

Is it brass, or bronze? Annealing brass is simple, heat it up and plunge into cold water. Bronze (several different alloys) is another animal altogether, I have had mixed results when attempting to anneal, and most were bad.

 

[paulvallandigham]

Mike Brooks: You are correct, and I was wrong. What I wrote was what I was told by a shop teacher more than 40 years ago. As I wrote, I have never seen any reason to harden brass, so I have never done what I was told( heat it and slowly cool it to harden brass). I recall him talking about realigning the molecular structure of the brass to return its tensile strength etc., only because I was playing the trombone in high school, the biggest piece of brass I owned at the time.

I looked up the subject of hardening brass here on the internet to see what they said, and they even indicate that dousing the brass in cold water is unnecessary to anneal it. All water does is speed up the time when you can handle brass. Once it is red hot, it softens, and you can quick cool it in water, or just let it air cool. It will be soft.

The materials indicate that hardening brass is done by compression and bending and hammering it. So, work " hardening brass may actually be a misnomer, in that any work on brass will harden it.

Thanks for making the correction. It only took 40 years for me to learn the right way to harden brass.

 

[redwing]

I have heard that placing it in molten lead is a good way to get an even annealing, never tried it.

 

[paulvallandigham]

The melting temperature of lead is 621 degrees F. The melting point of Brass varies depending on the proportion of zinc present in the alloy, but begins at about 1660 Degrees F.! I don't know at what temperature brass turns RED, so its your guess whether putting brass in molten lead will heat it enough to anneal it.

 

[LRB]

Paul I am impressed. It takes a good man to admit he is wrong, especially in such a large group. I started to post, but decided to pass on it. Hats off to you!
:hatsoff: :hatsoff: :hatsoff: :hatsoff:

 

[mbw907]

Hats off to you, Paul. We all can learn something new everyday. The only way that I ever knew to harden brass was to work harden it. But I bet someone here could teach us a different way. I never have needed to harden brass, either, but was always curious. Maybe with nitrogen?

 

All the above info is good iffn it's brass. The only problem is most of the time ya can't tell the difference between brass, and bronze til ya got two pieces. The only maker I know of that I'm sure of is Reaves Goering. All his components are cast from old rifle casings, and are very soft from the gitgo. They are a joy to work with, and components can be mixed and color match beautifully. No reddish, and orange tint, all nice yellow color.

Bill

I started with nothing and still have most of it left!

 

[paulvallandigham]

Bill: Its even worse that that: According to the net information I found, there are two different kinds of brass commonly produced and sold here: Yellow Brass, which has more zinc in it, and Red Brass, which has a very small amount of zinc, tin, and other trace elements. Red Brass has a much higher melting point.

Most of what we see as cast parts will be Yellow brass, but if you buy brass from a wholesaler, " Let the Buyer Beware ".

Thanks for the compliments. I guess its a little easier for me to " eat crow " than others, because I am a lawyer, and you don't win them all, even when you should. My brother reminded me last night that even our father taught us that you could harden brass by slowly cooling it. So, I suspect that misinformation has been around in one form or another for many years. I just wanted everyone to know the truth about it. I can live with my still red ears. But, I do thank Mike Brooks for pointing my mistake out here. Its how we clear things up.

I seem to recall most of us were worried about static electricity setting off black powder, until some enterprising fellow put a link on this sight to a set of pictures, and a short filmclip showing electricity being purposefully passed through black powder and nothing happening. I thought that took guts, then, and see that the issue still comes up when talking about powder containers for storage. Oh well.

 

[Mike Brooks]

But, I do thank Mike Brooks for pointing my mistake out here. Its how we clear things up.

No big deal here, I just wanted those reading to understand how to aneal brass is all. Either quenching or air cooling will work. I almost always quench because I'm in a hurry to get on with the work at hand. :winking:

 

[RedFeather]

Good stuff to know. I've never had a need to soften/bend brass but was looking at an old rifle that had some serious fit issues with its hardware and figured it would mostly have to be realigned. Ended up passing on it, but that's the kind of info I would have needed.

On recasting brass, I remember about twenty years ago watching a film on gunmaking in Williamsburg. The colonist wanting the rifle had supplied the gunsmith with a broken candle stick and some other brass odds and ends, as brass was hard to get. The narrator talked about how you can only melt/re-cast brass so many times before it becomes too brittle (one reason the colonies weren't too happy about the import acts.) I wonder if you try to anneal it a couple of times if this will occur, as well?

 

[Zonie]

In my old Materials Engineering book it lists 13 different kinds of Brass (Copper, Zinc and sometimes Lead). The percentages of Zinc and Lead vary
from Red Brass (Cu 85%, Zn 15%), Cartridge Brass (Cu 70%, Zn 30%), Yellow Brass (Cu 65%, Zn 35%) Free Cutting Brass (Cu 61.5%, Zn 35.5%, Pb 3%), thru Leaded Naval Brass (Cu 60%, Zn 37.5%, Pb 1.75 %, Sn 0.7%). Although it is usually associated with Bronze, Tin (Sn) is in 4 of the Brasses listed.

There are 14 different types of Bronze's is listed with Copper and Tin as the major metals however, there are some Bronze's which also contain Iron, Aluminum and Manganese. There is even one alloy (Coronze) which contains Copper, Aluminum, Tin and Cobalt!

The annealing temperature for all most all of the Brasses is 800-1100 degrees F. That would put it in the "Black/Red" to "Dull Red" heat range so I guess I've been overheating my brass parts. :grin:

As for Brass becoming brittle from remelting IMO, this wouldn't be the case for annealing.
The annealing temperatures are low so the material doesn't liquify. The only areas where the low melting temperature metals (Tin, Zinc, Lead) would have the freedom to escape would be a microscopic depth on the surfaces.

zonie

 

[TANSTAAFL]

Reloading, wildcatting and brass reforming, learns one early on, the in's and out's of annealing brass cartridge cases to a dull red in a dark room.