Thread: Annealing Brass

I'll just start another thread to avoid confusion.

Annealing is the process of softening metal.

Brass or other non ferrous copper based alloys harden by working, e.g. hammering, bending, forming etc.

Annealing brass (Cu + Zn, or in the case of Nickel Silver = Cu + Zn + Ni) can be accomplished by heating and either slow cooling or quick cooling as in a quench. Both methods will accomplish the same goal. The quick method means you get back to work faster, no more.

Personally I have never tried the quench method, but I have been using the slow cool method for 29 years on cartridge brass and never had a problem, and for 3 years on brass rod/pins and never had a problem....

I'll stick with that...

Mike, thanks very much for this information.I hope that it will clear the air of any confusion. I know I was getting confused but that isn't very hard to do.
So, either way will work.

The difference between a quick quench and a slow cool is the size and pattern of the micro-grain structure. A very slow, long duration cool (equivalent to leaving in a furnace and lowering temperature over a long period of time) results in minimal grain formation, and very large grains. A quick cool will result in very small grain structure. Both have their uses in different metallurgical applications. Neither one is better than the other although one process may be more suited to the application that it is being applied to. I anneal my bullet casings so that I may reload them many times without the work hardening splitting the bottle necks, I only heat the necks of the case and once they are at the proper temperature, I push them over in to a water bath. Hope this helps.

6gun,

Contrarian that I am, I have always used the quench method when annealing cartridge cases and this is only because I don't want to have to delicately deal with a bunch of hot brass tubes close to where my fingers might be. The hotter the tube, the more proximal my fingers inevitably will desire to get. It's much easier for me to pitch the case into a bucket of water and stanch the urge to play chicken with some hot metal.

Bruce do you use the Flame or the Stove method????

I believe that is the recommended method for annealing/normalizing brass for that purpose. All the guys that I know that are reloaders do it that way.

Originally Posted by mwillsher

The difference between a quick quench and a slow cool is the size and pattern of the micro-grain structure. A very slow, long duration cool (equivalent to leaving in a furnace and lowering temperature over a long period of time) results in minimal grain formation, and very large grains. A quick cool will result in very small grain structure. Both have their uses in different metallurgical applications. Neither one is better than the other although one process may be more suited to the application that it is being applied to. I anneal my bullet casings so that I may reload them many times without the work hardening splitting the bottle necks, I only heat the necks of the case and once they are at the proper temperature, I push them over in to a water bath. Hope this helps.

Dang, since I'm not dealing with cartridges and only with brass rod, what would be the best way to anneal.

For rods and pins, you can quench them or let them air cool, either way will give you satisfactory results for the intended purpose. The water bath is just one more thing to set up.

6gun,

I rotate the cases between my thumb and forefinger while I put about 3/4-7/8" of the neck into a propane torch flame. I ease the case in and out of the flame until I get a bluish purple oxide on the brass and then pitch it into a bucket of water. This method has cured the blow back soot streaks I'd get on the Starline .45-70 and .45-90 cases I use for black powder cartridge rifle shooting. When I use this technique, the head and rim may get only warm.

I made lots of assumptions here in that I don't have temp crayons or fancy digital sensors, I just tried to match the oxide color that I saw on on some high end bottleneck commercial cases. It seems to work. (I picture the village smith tempering some tools using the progression of oxide colors to determine what the hardness will be - ifor me it's only best guess as I don't even have a spreading chestnut tree ).

Bill, you need to get the brass to about 670 degrees to get it soft. If you heat it red, it will become dead soft -- too soft for a cartridge case, but may work OK for a rivet, and red is an easy heat for a propane torch.