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help forging brass


ironsmith

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hello all,

I was just trying to forge some brass today and i can't seem to get the temperature right.

my first heat would work really well but once i took another heat it would crack or fracture off.

could someone please give me some pointers on forging this metal?

THanks

Jody

by the way its c360 alloy if that helps.

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I have no idea whether that grade is even forgeable but I had to forge a bunch of brass for a customer one time all different alloys. I had much better luck forging with a press rather than a hammer and also using swages. I don't know if that helps or not. I have also upset an odd bronze alloy for a customer and did it cold. If you need to use the alloy you are using maybe annealing it and forging it cold would be more do-able.

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thanks for the suggestion JN, I am trying to do bracelets from brass out of 1/2 inch stock , not sure annealling would do for me.

I think its more temperature specific than copper. I am sooo new to non-ferrous forging it's all an experiment right now. I guess i just gotta pay more attention to

the heat on it.

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cool, that's what i was thinking. I was going to above a dull red on my first heat, and it forged well, then on the second heat it would fracture and mush.

will give it a go with a lower temp next time i am at the forge!

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Common brass if there is such a thing is next to impossible to forge, just bending it is a flail. It's full of lead and zinc so burning it is a hazard. If you really want to forge brass get alloy 464


C360 Free Machining Brass Minimum Properties Ultimate Tensile Strength, psi 58,000 Yield Strength, psi 45,000 Elongation 25% Rockwell Hardness B78 Chemistry Copper (Cu) 60 - 63% Zinc (Zn) 35.5% Iron (Fe) 0.35% min Lead (Pb) 2.5 - 3.7%

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I had a friend that used to make belt buckles out of large diameter brazing rod, 1/4", and he was always bending it hot and smashing it with the hammer but when I'd try it all it did was fly apart in little crumbs. I had better luck with silicon bronze rod but it was sure a lot more expensive to play with. Right now I'm working with some brass rod making some jewelry and I'm annealing it, then cold working it until it gets to hard to work easily and then re-annealing it. Brass just ain't at all like copper, it must be the zinc in it that makes it get brittle. I like to make tendrils to go along with some of my stuff and after drawing out the brass rod even after annealing it, it dose tend to be brittle and crumbly. I wish that I could get a hold of some of the older brass that had a touch of lead in it but since California doesn't allow lead in brass anymore it is hard to find.

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  • 3 weeks later...

I would advise you not to use the lead bearing brass. As I found to my cost it introduces another problem with getting the heat right. When the lump in the story below broke, you could see tiny beads of lead on the break surface.

I am very happy to be corrected by a metallurgist, but I was told that the lead is used to help the chips break when the metal is being machined. It enables this because it does not alloy with the copper but remains in suspension and forms a series of weak points throughout the brass on a microscopic level. Because it has a lower melting point than the copper, at the bottom end of the temperature range when you could normally work non-lead-bearing brass the problem is at its worst because the lead is almost molten but the copper is still relatively hard and it shears across the lead. The only way you can forge it hot is at the top end of the brass forging temperature range when there is less of a difference in ductility between the two.

My story....Back when I was more adventurous than I am now and nobody had told me I couldn't, I designed and made some church door pulls in brass.

In my happy state of ignorance I ended up buying 100 pounds worth of standard free machining, lead bearing brass for a job I was getting 200 pounds for. I bought enough 100mm x 25mm (4"x 1") to make three of them in case I screwed up, took most of the morning trying to draw out the first one. Despite being so careful to work it not too hot or cold I managed to get a crack and it fell apart, disaster. My friend and colleague Mike Roberts along the road had a TIG and welded it up for me and I spent the whole of the next day teasing out the next one, using the repaired bit as a handle. My nerves could not take another 8 hours of that, so on the third day I threw caution to the wind and forged out the last one by getting it to dull red and hitting it hard in 20 minutes flat!

The coincidence in this and reason for the tale is that I came across the 27 year old broken bit the day before this thread started and had cut the bit off and had started to machine up some tube plugs, see photo.

The door pulls were okay but you can see the difference. The one that took ages has a fold line running up it and the one that went through proper is much better formed.

post-9203-0-02609100-1340825099_thumb.jppost-9203-0-34729400-1340825120_thumb.jppost-9203-0-93960000-1340825139_thumb.jppost-9203-0-82855500-1340825161_thumb.jp

Brass forging subsequently I have used Delta metals DB4 when I could get it and more recently Coldur A which is Columbia Metals silicon bronze...almost as easy as steel to forge!

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Those pulls turned out very nice. 464 would have been a breeze.........
My friend Max Brun did this rail ages ago from architecural brass/bronze and it has always astonished me. To do a large railing with such temperamental crap. I hate the stuff. The cap rail is that extruded stock you can get from Blum or Braun and just bending it requires you do it in a darkened room to see the faint red at which it can be coaxed.
He forged the scroll ends at the above mentioned ever so dull red heat ...One of the trick to welding this mung is to actually dip the electrode into the puddle,sounds crazy but it works....It works on 464 too.

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Those pulls turned out very nice. 464 would have been a breeze.........
My friend Max Brun did this rail ages ago from architecural brass/bronze and it has always astonished me. To a large railing with such temperamental crap, I hate the stuff. The caprail is that extruded stock you can get from Blum or Braun and just bending it requires you do it in a darkened room to see the faint red at which it can be coaxed.
He forged the scroll ends at the above mentioned ever so dull red heat ...One of the trick to welding this mung is to actually dip the electrode into the puddle,sounds crazy but it works....It works on 464 too.

http://www.maxbrun.c...lStairrail1.gif


Wow, apart from the sheer mastery of the material, I kept looking at all those halving joints and cringing!

I must experiment with your electrode in the weld pool trick, I managed to get a lot of spits and bangs when I last tried to TIG some brass so I gave up and reverted to Easyflo silver solder.
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I must experiment with your electrode in the weld pool trick


The reason (I think) this works is maybe the arc is subdued a bit and inhibits the vaporizing of stuff like zinc and lead to a more acceptable level....It's still not pretty, like tiging silicon bz which doesn't need this technique.
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Good info, guys.

I too have been revisiting all that I feared about brass/bronze since i've been making more of these little bottle openers lately. I was using sili-bronze which I absolutely love but was just quoted 17$/lb. It was 14$ last year and I thought that was horrible. Turns out Naval brass is only about $10/lb. I hadn't ever used it but heard it was forge-able and am happy with the results. Looks like yellow brass but yellow brass falls apart as soon as you try to move it.

2nd photo is a sili-bronze filler on architectural bronze handrail. Filthy stuff. I was told to ditch the welding on bronze handrail, make your joints as tight as possible and silver solder. Seeing as how no-one has ordered a brass handrail in ten years it may be awhile before I try it.

post-12478-0-83120400-1340989478_thumb.j

post-12478-0-82537200-1340989558_thumb.j

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One thing about alu silicon bronze (642) not mentioned in charts is it WILL NOT ANNEAL, great forgeability at 80 but it's tough as nails when it cools. That fact cost me big bux one time....


http://www.google.com/url?sa=t&rct=j&q=forgeability+rating+of+bronzes+table&source=web&cd=1&ved=0CEcQFjAA&url=http%3A%2F%2Fwww.metalpass.com%2Fmetaldoc%2Fpaper.aspx%3FdocID%3D297&ei=8ujtT_zLDced6AGQ56mcCg&usg=AFQjCNHToc41BrkFIsvEgK8G5Sm1Kk5jtA&cad=rja

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70/30 brass (CDA 260) forges on the bad side of just OK
Unless it "has to be brass" I suggest the 655 silicon bronze that Atlas metals sells. It forges well and the only time I have any issue was when I was not paying attention to the heat...now I idle the gas forge with a thermocouple reading the temp and simply work...so it does not overheat.
I have done tennons, knots, tight bends and long tapers with zero issues.

I never had any luck with 360 brass on the hot side and save it for just machining....yes it is the lead which makes for breaking chips.

Ric

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  • 3 months later...

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