Can Someone Explain Annealing Brass

Status
Not open for further replies.
D

DMW1116

Member
Joined
Oct 10, 2020
Messages
4,246
I've seen a couple threads mention it lately. Why do it? How to know when? How to do it? Etc. I'd like to look into it a little deeper, but I haven't done it, and wouldn't know if I needed to.
 
Brass will work harden every time you fire it. This can lead to cracking. Annealing makes is soft and more malleable. Generally I use a small propane torch to heat the neck areas to visible red. Annealing also makes the brass easier to reform particularly using a neck sizing die.
 
Well explained by EIT above. Lots of vids and tutorials on how to. Keys are to get an even application of heat to the area being annealed and ensuring you don’t anneal the case head.
 
You should never wing it, you can ruin your brass trying to anneal it.

You need some Tempilaq (400 degree) at the minimum to get it right. You only need the case mouth and shoulder areas to get touched by heat, not the whole case.

If you have any mechanical abilities, you can go online and look up how to build your own annealing machine. That will help you out a lot, keep the torch in the right place and hit it with heat for the proper amount of time.

If you don't, check out the Ken Light annealing machine. Not cheap but it can do all your brass in hours, not days.
 
When I have annesled brass I used the method @EccentricInTexas mentioned, only I stand my brass in a pan with about 3/4” of water in it. When the shoulders and mouth of brass are hot I knock them over to cool in the water. Seems to work out just fine.
 
DMW1116 said:
Why do it?
Click to expand...
To keep the same neck tension across all the brass, and through each loading cycle. To also soften the brass to keep it from splitting.

DMW1116 said:
How to know when?
Click to expand...
For consistency in neck tension it should be done every cycle. For brass longevity, while saving some work, every third cycle.

DMW1116 said:
How to do it?
Click to expand...
With an Annealeeze automatic annealing machine!:)
Or one built by hand.
Or the Socket and Drop It method, spin a deep well socket in a drill with the brass in it, just the neck sticking out. Hit it with a torch to a five count.
Water is unnecessary, and needs to be dried off. The head will not get enough heat to soften, unless you’ve ruined the neck already.
In fact, a red glow is too hot.

I like the Annealeeze, but I think I could have built one just ever so slightly better, and red, not grey.
 
EccentricInTexas said:
use a small propane torch to heat the neck areas to visible red.
Click to expand...
If the brass goes red, it's effectively toast.

From Uncle Nick:

Back in the 1960's, Wm. C. Davis investigated the common practices at the time, commenting:

"Most reloaders excessively heat the necks, causing formation of a large-grain brass structure, extreme softness, and lack of 'spring', or ability to hold the bullets in the necks. This results from the usual advice, "Heat the case necks until red hot and then knock the cases over into water". While the neck so treated are indeed unlikely to crack, they may be so soft that they can be squeezed together between the fingers, which is a good way to judge their relative softness."

Rule of Thumb for high-pressure/bottleneck rifle brass:

- Re-Anneal every 5-6 loadings
- Use a socket spinner, propane (not MAP), and tempilaq to control temperature

See https://thefiringline.com/forums/showpost.php?p=6105757&postcount=2
 
Haven’t loaded bottle neck rifle brass in decades now but when I did my standard practice was to stand the cases in a pan of water deep enough to come half way up the case. The mouths and shoulders were then then heated with a torch until they glowed red. The case was tipped into the water.
I had read of this technique in a hand loader magazine I believe.
 
Like said earlier, it's to make uniform neck tension every cycle. The upside is you no longer get neck splits. Over heat the brass and it's toast. Use the Temp-Lac to get your time and distance right. There are may ways to do it. The main thing is you want consistency.
 
MEHavey said:
If the brass goes red, it's effectively toast.

From Uncle Nick:

Back in the 1960's, Wm. C. Davis investigated the common practices at the time, commenting:

"Most reloaders excessively heat the necks, causing formation of a large-grain brass structure, extreme softness, and lack of 'spring', or ability to hold the bullets in the necks. This results from the usual advice, "Heat the case necks until red hot and then knock the cases over into water". While the neck so treated are indeed unlikely to crack, they may be so soft that they can be squeezed together between the fingers, which is a good way to judge their relative softness."

Rule of Thumb for high-pressure/bottleneck rifle brass:

- Re-Anneal every 5-6 loadings
- Use a socket spinner, propane (not MAP), and tempilaq to control temperature

See https://thefiringline.com/forums/showpost.php?p=6105757&postcount=2
Click to expand...
I had not read your post, it makes sense I suppose. Loading and reusing 308 358 and 30/06 in the 70’s and 80’s into the 90’s I used the technique as described. Perhaps I was lucky as I seem to get several reloads before other signs of brass failure scrapped the cases. I load only straight wall pistol brass these days and don’t bother with annealing.
 
The front of the case needs to be soft so it can easily expand, releasing the bullet, but, more importantly, expanding/grabbing/sealing the chamber so the hot high pressure gases cannot escape to the rear. The back of the case has to be hard enough and sound enough not to rupture under pressure, letting hot high pressure gases escape rearward.

Making cases work hardens the brass, so makers anneal the neck/shoulder area. As we fire and resize the case over and over we re-work harden the front of the case again (Neck/shoulder area) and it starts to resist sizing and springs back leaving us with less neck tension than we had, and at some point, not enough, not to mention the neck will split sooner if we don't anneal.

Some anneal every time for consistency, some anneal as needed, every third/fourth time.

As posted above if done wrong we have damaged the case. If we soften it towards the rear it can be dangerous. That said, annealing is a natural part of making brass, and like anything else if done correctly is not dangerous and can help case life and consistency of sizing.

I don't bother with .223/5.56 range brass for plinking because I get 8 to 12 reloads with perfectly acceptable results before I start losing them to loose primer pockets. Not worth it in that application.

My 6 Dasher brass for PRS? I anneal every time although some don't and only anneal as "needed".
 
What temperatures are needed? How hot is red hot? I have some references from school. I'll see what I can dig up. I'm familiar with heat treating and annealing of steel, but brass is different I'm certain.
 
I'm actually just looking for a starting point. I think I've seen references for salt bath annealing set ups? Is that a thing?
 
Last edited:
DMW1116 said:
What temperatures are needed? How hot is red hot? I have some references from school. I'll see what I can dig up. I'm familiar with heat treating and annealing of steel, but brass is different I'm certain.
Click to expand...

With reloading, although we refer to it as "annealing" we are really "stress relieving". If we want to anneal a sheet of brass, maybe as in some craft work, we would raise it to red heat and hold it there for a short time. This softens the brass ready to be re-worked, quenching with brass is immaterial, water or none makes no difference, although it might then be pickled in acid to remove the oxides.

Annealing in this way, by heating the neck to red heat will make the neck too soft, possibly deforming when sizing or seating the bullet and lacking any "spring" for consistent neck tension. Annealing brass it not just about temperature, it also has a time component, but in general, for out purposes, very little effect takes place below about 650F, around 700 -850F held for 3-4 seconds looks to be the golden area. Once above the 1000f mark you are moving into "fully annealed" territory.

Induction annealers raise to a higher temperature for a shorter time for similar results.

Temperature sensitive "paint" called Tempilaq is recommended until you have the "feel".
 
I've seen a couple threads mention it lately. Why do it? How to know when? How to do it?
Click to expand...

Me too. Reading some suggestions on how to do it, in relation to the why they are doing it, I have come to the conclusion some folks have never tested their methods vs other methods or just not annealing at all. You don’t want any glow of any shade of red or orange, for example.

There are a number of methods that would likely give less satisfactory results in the accuracy/consistency aspect than if they were just shot until split.

Now, I am not an annealing “hater”, I even sell machines as well as parts and plans for others to built them. So it can be helpful, if done correctly.

This is a good read on the subject.
https://www.6mmbr.com/annealing.html
 
I've tried several methods, including the propane torch method. For me, the "salt bath" method is the easiest and most consistent.

Annealing is roughly linear with time and cubic with temperature. You can anneal at a low temperature for a long time, or at a high temperature for a short time. The old metallurgists would apply heat until the bluish oxide film formed on the brass, and that is the way I did it for a while. It worked. I used my wife's gas range.

The water bath is useful for keeping you from burning your fingers on hot brass. It has no metallurgical effect.

To answer the question about "salt bath" annealing, here is a video I made. BTW, brass and hot nitrates are compatible, and don't cause corrosion unless you don't clean the brass afterward.



Shopping list: Lee lead melter pot, $40; temperature controller with solid state relay, $14; lab stand and burrette clamp, $25; one pound each of potassium and sodium nitrate, total $20; K type thermocouple, $5.
 
Last edited:
EccentricInTexas said:
Brass will work harden every time you fire it. This can lead to cracking. Annealing makes is soft and more malleable. Generally I use a small propane torch to heat the neck areas to visible red. Annealing also makes the brass easier to reform particularly using a neck sizing die.
Click to expand...

Visible red is much too hot for brass. Visible red is for steel and brass anneals well below the red spectrum at 650 to 700 degrees. If you don't believe me look up a website by an actual metallurgist about the properties of brass. I even see on the internet where people say unlike steel that gets harder when you heat it brass softens. Duh, both soften with heat but at greatly different temperatures. There is a ton of brass annealing information available on the internet and just like every other subject a lot of it is false.
 
Status
Not open for further replies.

Similar threads

C
  • Locked
Annealing
Replies
14
Views
839
jmorris
jmorris
R
  • Locked
Talk to me about proper annealing technique
Replies
19
Views
6K
docsleepy
D
J
  • Locked
Is Annealing 22 Hornet Brass Worthwhile?
2
Replies
26
Views
2K
HowieG
H
WestKentucky
  • Locked
Please break down annealing for me from a metallurgical point
Replies
24
Views
1K
Walkalong
Walkalong
1942farmall
Annealing Brass
Replies
2
Views
265
jmorris
jmorris
Back
Top