Brass and Bronze Forging

Forging brass, bronze and copper alloys

George Dixon calls for using 16 gauge naval bronze and describes it as having good hot forging and cold chasing properties. Only problem with it is that it doesn't seem to exist. I called my local scrap dealers, the warehouse at the fabricators I deal with, and two metal dealers in Richmond. The closest thing they had was some HIGH dollar 1/4" diamond cut plate that had to be imported from one of those Pacific Rim countries called California.

My efforts once again insured me of a place on the far left side of the research curve. I have absolute confidence in the fact that if George Dixon said he was using naval bronze, that is what it was. He probably found it at the Yellin shop and it had probably been there since WWI.

1. What is naval bronze?
2. Where does it live?

L. Sundstrom - Wednesday, 06/20/01 20:32:53 GMT

Naval Brass: Larry this is most often mistakenly called Bronze, it is a brass. Also nearly the same as Muntz metal C28000.

Alloy 464 or C464000 to 467000

Cu 60%
Sn 0.8
Zn 39.2

Forgeability 90 compared to Forging brass alloy #377 at 100. This is similar to Cartridge brass. We have cartridge brass C26000 in our on-line store in almost any size and thickness you want.

C26000

Cu 70%
Zn 30%

The trick is that MOST of this stuff is delivered as-rolled in a hard temper. If you anneal it then it works like butter. Try forging some large brazing rod at a low red heat. . it says BUTTER! (like the TV commercial)

- guru - Wednesday, 06/20/01 23:06:08 GMT

Jock,
Thanks, that really clears it up. one guy kept saying naval brass and I kept correcting him. "No, I said, BRONZE"

I also heard the word "Muntz" and I said "No, I want bronze". So, want should I ask for if I don't want the typical brass look, but want the look and color of what I am thinking "bronze" statues have. Would the C26000 you have in the store work. Maybe its a question of finishing rather then of materials. I've seen silver colored brass so maybe I have a mistaken concept of brass, origin...DRILL SARGENTS(grrrrrrrrrrrrin). Thanks,

Larry Sundstrom - Wednesday, 06/20/01 23:53:31 GMT

Brass vs. Bronze: Larry, "Brass" is Copper and Zinc. "Bronze" is Copper and Tin. Like brass the high copper bronzes are the most forgeable. "Gilding Bronze" is similar to one of the more forgeable bronzes.

When shiny brass looks very gold in color. Bronze looks more coppery. When well oxidized or patinated they both have a very similar green.

- guru - Thursday, 06/21/01 02:46:09 GMT

"Forging Brass" UNS C37700
Copper 59.5%
Lead 2%
Zinc 38%

"Architectural Bronze" UNS C38500.
Copper 57%
Lead 3%
Zinc 40%

Frank Turley - Wednesday, 08/15/01 22:38:42 GMT

Adam Smith - Thursday, 05/10/01 20:01:00 GMT

Brass, Muntz: Adam, most of these alloys show a slight blush just as they reach forging temperature. A little hotter then they melt. Generally these alloys don't fall apart too bad unless they have some lead in them. Many have lead to make them easier to machine.

- guru - Thursday, 05/10/01 20:22:41 GM

There are MANY monels including some sold for architectural work. Monel 400 is one of the most common and is the most forgeable. It is worked at 1700 to 2150 (max) F. and shouldn't be soaked for long periods of time.

The most forgeable of the copper alloys is Forging Brass followed by Naval Brass. These are worked at around 1300°F. In bronze the Mangananese-Aluminium bronze is the most forgeable being 75% as forgeable as Forging Brass. Remember that brass and bronze is denser thus heavier than steel but it is not as strong so sagging is a serious problem in gates.

The biggest problem with working both these materials is removal of the oxidized surface. This requires pickling or sandblasting. It is a LOT of work if you want bright metal. This has to be done before polishing (another expense) which is very labor intensive.

The second problem is temperature control. Brasses and bronzes melt just a few hundred degrees above the forging temperature. It can be done in a coal forge but is very tricky. I always used a torch. You should plan on a temperature control furnace.

Actual forging of these metals is like working hot butter. Much detail or final work is done cold (or warm) the heat having annealed the metal.

I also recommend 304 stainless. It is a little more difficult to forge than mild steel but the resulting surface looks just like fresh forged steel. It also has the cleaning problems above. However, I have had good luck with out cleaning. You can use a combination of the black with polished highlights that works nicely for details.

Beware of bimetalic corrosion from attaching items made of these alloys to each other or to other metals. Be especially careful not to use fasteners of dissimilar metals. - guru - Saturday, 05/12/01 17:08:14 GMT

Greg Clasby - Saturday, 11/25/00 01:12:55 GMT

Brass: Greg, Brass has a very narrow forgability range but forges easily in that range. A lot of the brass bar stock you find is leaded free machining stuff for screw machines. The lead separates if the brass is slightly overheated and the brass crumbles. .

A good source for lead free forgeable brass is uncoated brazing rod. It comes in rounds up to 3/8" (9.5mm). However it takes some searching to find a welding supplier that will sell part of a container.

McMaster-Carr sells Naval Brass (Alloy 474) which is one of the most forgeable copper alloys.

- guru - Saturday, 11/25/00 02:05:56 GMT

Brass: Here in Holland we have a series of different alloys of brass.If you want to hammer it you will have to use an alloys with a larger percentage of copper in it.

(Cu63,3-65%); Fe 0,05%max; Pb 0,05%max; Zn fills the rest of the alloy.

This is the alloy I use for smithing cups, bowls and boxes (the raising technique). There is and even softer alloy for spinning and die-stamping:

Cu 69-71%; Fe 0,05% max; Pb 0,05%max; Zn fills the rest.

We use it as sheet and as rod. The zinc is the metal that gives brass its hardness. The paler the brass the harder it will probarbly be.

Flux: In reaction to your answers first a thank you and then a slap in my own face. In silversmithing I use sulphuric-acid. The reason I didn't think of it,is because if I would use iron or steel in the acid and the use it for my silver, it would colour my silver an ugly pink which is very hard to remove. We use this acid also to remove our borax-residues. Borax is used for high-temperature soldering.

Dries Van de Voort - Saturday, 11/25/00 12:19:23 GMT

Dan Hale - Friday, 05/25/01 01:00:19 GMT

Brass: Dan, Case hardening is the result of iron or steel absorbing carbon to form a hard "case". Fancy case hardening colors are the result of a very special case hardening process that both hardens the surface AND produces those marbled temper colors.

No, brass doesn't case harden or flame color. It does WORK harden. It CAN be colored dull greens via harsh chemicals but it is NOT recommended for guns. Brass is used for places that are to be polished up real pretty in this type work.

- guru - Friday, 05/25/01 01:24:10 GMT

noiseyforge - Thursday, 02/07/02

Avoid Beryllium bronze. Beryllium dust is very toxic and produces pneumonia like symptoms so that it is rarely diagnosed until it is too late.

Beryllium bronze is used to make spark free wrenches, tools and springs.

- guru - Thursday, 02/07/02 18:21:38 GMT

References and Links

• Decorative and Sculptural Ironwork Dona Meilach's landmark reference.
• Brass Candle Stick Demo iForge demo by Jock Dempsey
• Galvanic Series Factors in bi-metalic corrosion.
• ASM Metals Reference Book, American Society for Metals International
• MACHINERY'S HANDBOOK, Industrial Press
• MatWeb.com On-line materials database