Proper flame annealing technique
- Thread starter TQB
- Start date
I'm going to walk a razor fine line here with an attempted explanation of " annealing " Because in BOTH terms it's correct . Simply a matter of interpretation as to the subjects criteria .
" The process or art of treating substances by means of heat, so as to remove their brittleness and at the same time render them tough and more or less elastic . "
" The act of heating solid metal or glass to high temperatures and cooling it slowly so that its particles arrange into a defined lattice. "
When we re-loaders/annealer's anneal ; What we're really doing in essence is returning ductility or malleability to the cartridges Neck/shoulder area . NOT restructuring grain alignment or recrystallizing grain structure .
The process for that requires a lengthy hold at specific temperatures . Exactly why so much confusion comes about on Temperature color time Etc. . Why I personally agreed with the gentleman from Sniper's Hide .
Those of us who've been around for a spell KNOW which cases are Better and more desirable .
Two contributing factors IMO ; Cu/Zn ratio and ANNEALING TEMP AND TIME make superior Cases .
Now as I NO longer seriously Bench Rest ,I generally DON'T turn necks anymore but once in awhile ,I will for grins . I've come close over the decades of stacking #5 into the same ragged hole . About the best I do now is 200 meter cover #15 handloads with a dime and far from a BR setup I assure you .
The 750 Deg. is an unwritten open flame bench mark so to speak . It could be 825 715 or 940 .
Some where between 725-825 the case neck will Glow dull red in a few seconds with a propane or butane Mapp gas open flame , properly pin pointed on that specific area . I DON'T recommend Turbo or Oxy/Acetylene torches as their far to HOT for the purpose of brass cartridge annealing .
I have MY setup with the blue flame tip 0.125- 0.1875 1/8"-3/16" aimed at the shoulder angle forward towards the neck and mouth . I altered MY machine as they're nearly 90 degrees in relationship to the torch tip . Mine is 22.5-30 degrees Eyeballing it
I try to redirect as much heat away from the case body as possible ,as it rotates in the annealeez .
I've tried using a remote infrared gauge but the open flame negates any real accurate readings .
When the neck turns dull red as per my tempilaq trials 800 Deg. tempilaq melts . Inside or outside the case neck makes NO difference . Neither does water quenching . I've never had a cartridge's base so hot I couldn't pick it up bare fingered , admittedly quickly . I DON'T recommend pinching the case above the rebated rim or belt on a magnum . So over a period of time , I experimented with several cartridges between .222-.338 Lapua and wrote down times . So cleaned cases get annealed ,then sized trimmed and so forth .
RegionRat
Gold $$ Contributor
@DocCarbon just curious, not calling you out.
Have you ever run any of the tests, measurements, or slide preparations we have been discussing in the citations yourself?
If you cold worked thin (say 0.014”) cartridge brass from a HV of say 95 and went back up to say over 150, have you seen crystallization changes?… in proportion to harness values? Ever run the tensile strength tests?
Have you ever run any of the tests, measurements, or slide preparations we have been discussing in the citations yourself?
If you cold worked thin (say 0.014”) cartridge brass from a HV of say 95 and went back up to say over 150, have you seen crystallization changes?… in proportion to harness values? Ever run the tensile strength tests?
BoydAllen
Gold $$ Contributor
There are a couple of issues here...at least. First of all, how to know how long to keep the flame on the case. My friend and I set up his two torch turntable annealer (that paused the cases in the flames for an adjustable amount of time) using three different temperatures of Tempilaq on a single set up case. After our experiments we settled on using a thin stripe of 500 degree down the case body, from the outside of the shoulder to the head. We would adjust the time until the Tempilaq darkened down to the point where the Lapua annealing colors show. The reason that we were annealing was to have more uniform shoulder bump for a couple of magnums, a 7mm WSM and a .338 Lapua. The first time through we annealed and then sized, but did not see the improvement in bump consistency that we wanted so for the next small batch we increased the time by one second. If memory serves I think that it was increased from 7 seconds to 8, but is has been years. Remember two torches. We set the torches to point the inner flame at the middle of the necks, about a half inch away. We were doing brass that needed to be kept hard enough for feeding heavy bullets from a magazine, keeping them secure under recoil. It worked. Although we did not think of it that way at the time, looking back, it seems that using uniformity of shoulder bump as an indicator to get back to the same condition of partial annealing (or stress relieving, or whatever you want to call it) may have some merit. Also, with everyone having a cell phone, one can keep a photographic record of what was done, what the flame near the neck looked like and how the Tempilaq darkened on the case. We just used the same case over and over to set up, cooling it and removing the tempilaq residue for each test.
I’ve settled on this test regimen.
Five cases were annealed at the following times:
At 7 seconds I got the faint red glow.
I will only be able to test on December 5th so results will only be available then.
Thanks,
Tiago
Five cases were annealed at the following times:
- 5 seconds;
- 5,5 seconds;
- 6 seconds;
- 6,5 seconds;
- 7 seconds.
At 7 seconds I got the faint red glow.
I will only be able to test on December 5th so results will only be available then.
Thanks,
Tiago
Hello, what is your flame annealer?
I use a Benchsource annealer, fwiw.
The BS uses 2 propane torches (not supplied), same as for brazing copper tubing.
While I'm not an expert, I have annealed many (ten's of) thousands of cases with good results, and it absolutely helps with accuracy and case life.
When in a dark room, set the flame to heat the case neck and 1/3 down the case - no more - to a dull red.
With the Benchsource, nearly always 4-5 sec per case.
The case after annealing is a silver gold color. Never used tempilaq. Anneal 1st, then size.
When using an arbor press to seat bullets, the benefits of annealing are easily felt. Hope this is of help.
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I have a AGS Brass annealer.
It only uses one torch. My only complaint with it is that due to its compactness, it is rather short. If you let some cases build up underneath the shute, they will end up sticking out and block the carousel. This can be easily overcome by putting something underneath the unit to raise it.
I hope to be able to answer that in a few weeks.
What I hope to get is more consistent neck tension.
I tend to have some bullets seat harder than others and I think that has contributed to larger ES/SD and goup sizes.
Either way it will cost me 25 cases. That's not a lot to get that question out of my mind.
I've spent an inordinate amount of time inside my former employers Lab , in excess of 24 years ,as well as nearly double that in My own Lab . Prior to My retirement , I was employed as a Materials Processing Engineer for a well known aerospace company . However 90% of MY work was Structural composites ,along with adhesives as well as a variety of coatings . So I hardly qualify myself as some sort of expert in that realm .
The only time I've personally seen crystalized restructure on brass . Where I noticed it predominately ,was when it was allowed 28 + minutes at 800 F. approximately 427 C. recrystallization was visibly noticeable under magnification . I did that inside a tempering oven and NOT open flame .
I can say Nothing happened at 400 500 600 deg. even held at 30 minutes as that was MY baseline . Now at 700 F a slight change and at 800 F. Dramatic change . Again held 28-30 minutes .
FYI : I used a number of 7.62x51 cases and as I'd ruined them by oven heating ,Didn't bother testing hardness ,I simply tossed them into MY Brass scrap when I got home . Lattice or structure particle alignment was smaller by perhaps 2/3's and orientation was very noticeable . Every once in a while early on ,I'd take a case I had torched at home and polished into work ,then place it under magnification and I saw Nothing .
I'd like to bring out a very valid point ; Everyone seems fixated on TIME or DWELL .
I don't believe there is a particular SET DWELL for open flame . Meaning torch temps will vary ,as do their flame shape and positioning relationship to the case it's self . Ambient temp. cold garage warm house Winter Summer . What I refer to as Variables .
It sounds to Me like a good number of you have spent some time as well as Money ,in the shooting arena .
So Might I suggest a Full or is it FOOL proof method
?. There are a # of Strain tension gauges within budget ,so as to verify what YOU'RE doing is correct for You .
Take some used cases which might be headed to the scrap bin ,a bullet or two in which ever calibers you're loading .
Drill an appropriate hole through the bullet's nose area ( what ever sticks out of the case mouth Not below it )
Now after seating your bullet in an empty annealed case , place either fishing line of appropriate strength or steel wire and pass it through the bullet up towards the nose ,tie it into a loop or use Nico press swage . Test Your neck tension on your bullet . You can use your press shell holder for the base anchor point ,run line up through where Your Die would be set gauge on top ,stroke downward ,see what the tension REALLY IS .
By YOU varying the Dwell and sizing your case seating that same bullet ( and case if you wish but it will need to be re work hardened before reusing it ) YOU will know exactly what You're doing in relationship to annealing . Some people want X amount of tension ,others X1/2 and XX . I'm sure You get the picture .
I've never annealed a usable case to where dis-colorization has passed more than 1/4" below the shoulder .
Look at a Lapua, Norma , LC or ?, to where their annealed or discolored . Stay Safe it's Not a race .
I don't believe there is a particular SET DWELL for open flame . Meaning torch temps will vary ,as do their flame shape and positioning relationship to the case it's self . Ambient temp. cold garage warm house Winter Summer . What I refer to as Variables .
It sounds to Me like a good number of you have spent some time as well as Money ,in the shooting arena .
So Might I suggest a Full or is it FOOL proof method
?. There are a # of Strain tension gauges within budget ,so as to verify what YOU'RE doing is correct for You .Take some used cases which might be headed to the scrap bin ,a bullet or two in which ever calibers you're loading .
Drill an appropriate hole through the bullet's nose area ( what ever sticks out of the case mouth Not below it )
Now after seating your bullet in an empty annealed case , place either fishing line of appropriate strength or steel wire and pass it through the bullet up towards the nose ,tie it into a loop or use Nico press swage . Test Your neck tension on your bullet . You can use your press shell holder for the base anchor point ,run line up through where Your Die would be set gauge on top ,stroke downward ,see what the tension REALLY IS .
By YOU varying the Dwell and sizing your case seating that same bullet ( and case if you wish but it will need to be re work hardened before reusing it ) YOU will know exactly what You're doing in relationship to annealing . Some people want X amount of tension ,others X1/2 and XX . I'm sure You get the picture .
I've never annealed a usable case to where dis-colorization has passed more than 1/4" below the shoulder .
Look at a Lapua, Norma , LC or ?, to where their annealed or discolored . Stay Safe it's Not a race .
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RegionRat
Gold $$ Contributor
I'd like to bring out a very valid point ; Everyone seems fixated on TIME or DWELL .
I don't believe there is a particular SET DWELL for open flame . Meaning torch temps will vary ,as do their flame shape and positioning relationship to the case it's self . Ambient temp. cold garage warm house Winter Summer . What I refer to as Variables .
It sounds to Me like a good number of you have spent some time as well as Money ,in the shooting arena .
So Might I suggest a Full or is it FOOL proof method
Take some used cases which might be headed to the scrap bin ,a bullet or two in which ever calibers you're loading .
Drill an appropriate hole through the bullet's nose area ( what ever sticks out of the case mouth Not below it )
Now after seating your bullet in an empty annealed case , place either fishing line of appropriate strength or steel wire and pass it through the bullet up towards the nose ,tie it into a loop or use Nico press swage . Test Your neck tension on your bullet . You can use your press shell holder for the base anchor point ,run line up through where Your Die would be set gauge on top ,stroke downward ,see what the tension REALLY IS .
By YOU varying the Dwell and sizing your case seating that same bullet ( and case if you wish but it will need to be re work hardened before reusing it ) YOU will know exactly what You're doing in relationship to annealing . Some people want X amount of tension ,others X1/2 and XX . I'm sure You get the picture .
I've never annealed a usable case to where dis-colorization has passed more than 1/4" below the shoulder .
Look at a Lapua, Norma , LC or ?, to where their annealed or discolored . Stay Safe it's Not a race .
So, in essence, you have zero experience or production responsibility of ordinance in relation to deep drawn annealed cartridges with respect to the standard tests, slides, etc.? Should that mean you are qualified to judge who else is or isn’t an expert?
Recrystallization, which is partial but very easy to find in cartridge necks, starts as low as 530F, instantly. It would take a long time at 530F to get a clear slide, but that doesn’t mean is hasn’t started.
That also isn’t to say it has a strong effect on the tensile tests, but is in relation to protecting the risk to body strength.
You don’t see this in cups or pucks (bulk forms) but is critical in cartridge sections. This is why we say to use 400 F in body sections to prevent weakening.
I suggest we don’t make very assertive comments regarding indirect knowledge of cartridge production based on being in a related field, and without any direct experience.
Nothing wrong with finding papers and discussing them, but best to follow up with the ones well before them and after them. Cartridge making technology is tightly controlled and not often published in the open. However, the old references are not wrong about annealing or cartridge making versus bulk brass.
The two papers you cited have serious conflicts between them. Later work at Norma had these issues pointed out to them and they would not make the same comments today that they did when they published those papers with respect to recrystallization. To be blunt, nobody cares about the grain structure once the mechanical properties are established.
There are no references to time or temperature in that Norma paper, just the power level of an unspecified induction system. No doubt they achieved their hardness survey goals before they ran with those power settings, but it means nothing in terms of the tensile strength or yield point changes, which is what we are really after.
The Norma paper is of no use to an annealer at home. It gives no time or temp values for actual cartridge necks, and if it did they would not be measured in minutes or in an oven.
At the end of the day, the true value of annealing would be directly measured in terms of a stress strain chart, but we end up using HV as an indirect measurement due to the difficulty of setting up stress strain tests on similitude of thin samples which do not behave as puck or cups in standardized tests.
During my tenure as a Chairman in ASTM, I discovered the difficulty of getting a whole committee to accept a test method that is new or different. You find it takes more than 5 to 8 years worth of biannual meetings to get close to a consensus, which may or may not pass. What i concluded was I didn’t care if the tests became a standard or not, nor did I care what the grain structure did as long as the cartridges performed. There were far too many folks voting in committees that were far from experts or directly involved.
All of that stuff published in ASTM using heavy sections, ovens, cups or pucks, has no relationship to cartridge neck properties. It is only used as quality control background on the bulk purchase of cartridge brass and has almost no useful relationship to cartridge necks.
The drill motor is in a swiveling vise,the clamp on table is the "stop". This way the neck/shoulder is always in the same place WRT flame. Point flame at an angle. Don't judge the gap here,it gets dialed in when using. If I was starting out,or wasn't such a cheapa$$,would buy one of the more modest commercial versions. Good luck with your project.
Here's the torch set up I put together.
My Country boy annealing set up **EDIT**
I finished it this morning, pretty simple but works well for my 260 and 22-250.
forum.accurateshooter.com
RegionRat : You asked the question ?
I didn't use pucks or cups only MY personal cartridge cases and the question was ; had I ever seen re-crystallization .
Did You not understand what I had typed ?
" So I hardly qualify myself as some sort of expert in that realm ."
The only time I've personally seen crystalized restructure on brass . Where I noticed it predominately ,was when it was allowed 28 + minutes at 800 F. approximately 427 C. recrystallization was visibly noticeable under magnification . I did that inside a tempering oven and NOT open flame .
As to MY personal qualifications : Does a PhD. in organic chemistry ,along with a MSEng from UCSD ,along
with being a batch chemist early in MY career for Hercules Powder Company ( industrial Division ) .
Good advice to follow :
I suggest we don’t make very assertive comments regarding indirect knowledge of cartridge production based on being in a related field, and without any direct experience.
I didn't use pucks or cups only MY personal cartridge cases and the question was ; had I ever seen re-crystallization .
Did You not understand what I had typed ?
" So I hardly qualify myself as some sort of expert in that realm ."
The only time I've personally seen crystalized restructure on brass . Where I noticed it predominately ,was when it was allowed 28 + minutes at 800 F. approximately 427 C. recrystallization was visibly noticeable under magnification . I did that inside a tempering oven and NOT open flame .
As to MY personal qualifications : Does a PhD. in organic chemistry ,along with a MSEng from UCSD ,along
with being a batch chemist early in MY career for Hercules Powder Company ( industrial Division ) .
Good advice to follow :
I suggest we don’t make very assertive comments regarding indirect knowledge of cartridge production based on being in a related field, and without any direct experience.
Here are some photos illustrating what MY .308 annealed cases look like , also after polishing . Which I don't do for any extended period of time . Generally I use Military cases as I've got several vintage as well as New AR platform guns 7.62x51 and 7.62x63 ,aka .30 cal .
These particular cases are #1 fired LC 1952-53 and 54 . With #15 re-loadings on them and annealed every #3 Rd. firing . I have several K's of both . Unfortunately they were left to the weather for better than #40 years I know of ,before I acquired them . Total time from grungy to re-loadable takes 1.5-2 hr. including drying time ,which I don't use forced air or oven , just a case media separator with a fractional Hp motor to turn it over continuously . Two for one ,as it ensures everything is out of the case and it's dry .
Cleaned cases annealed using the term loosely and far right case 20 minutes in the polisher .
Commercial cases clean and shine far better than Military brass or at least far quicker in MY experience .
These particular cases are #1 fired LC 1952-53 and 54 . With #15 re-loadings on them and annealed every #3 Rd. firing . I have several K's of both . Unfortunately they were left to the weather for better than #40 years I know of ,before I acquired them . Total time from grungy to re-loadable takes 1.5-2 hr. including drying time ,which I don't use forced air or oven , just a case media separator with a fractional Hp motor to turn it over continuously . Two for one ,as it ensures everything is out of the case and it's dry .
Cleaned cases annealed using the term loosely and far right case 20 minutes in the polisher .
Commercial cases clean and shine far better than Military brass or at least far quicker in MY experience .
The OP was asking for info on tempilaq and dull red case glow when annealing.
RegionRat
Gold $$ Contributor
@DocCarbon , Since Covid, most face to face meetings and conferences have been a disaster. They were not doing well even before Covid. Hard to say when they would even start up again and what damage will result to the attendance.
Your background would mean you would be up to speed in no time flat if afforded access to the materials. Facility tours were rare but probably the best way to really learn what it means to take bulk brass and turn it into centerfire or rimfire ammo.
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