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what brass to use for forgings?


meco3hp

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Hello,
I've got a small project that uses brass to make forged tapers in a rectangular shape. Anybody know what brass alloy to use? My Machinert's handbook calls out old SAE "standard" numbers. I doubt anybody locally would even have the slightest idea what I was talking about.

Thanks
Richard

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Are you hot forging or cold forging the brass?

The annealing suggestion is only for cold forging.

Hot forging is trickier as you have a narrow temp range.

Avoid all leaded brasses for hot forging.

I don't know the alloys I generally end up testing stuff till I find some scrap that works.

IIRC navel bronze and silicon bronze are supposed to hot forge ok. (temp is when it's *barely* glowing in a completely dark room)

Thomas

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  • 3 years later...

655C is the only bronze that should be forged with health in mind. The lead content as noted above is about .2%-.5%. Any other bronzes will have higher lead count in them.
As noted above as well, Even a propane barbque will melt this bronze into a hott puddle on the floor of your forge. Orange is way too hot. If it gets this hot let it cool to dark red before attempting to blink. I tried working 2 pieces in the propane forge and found that I did not feel like a PRO, but did feel the PANE. One at a time! I just bought 5/8" round and it is about $11 a foot.

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Both Silicon Bronze C655 and non leaded Naval Bronze C464 forge well but the 464 has twice the forgeability rating of the 655 [80 as opposed to 40] It is also quite a bit cheaper. The color is more yellow brass than the reddish brown of the Silicon Bronze.
Both of them are hot short and won't survive long at over a low orange heat so it is essential to pay close attention and keep the shop lights dimmed. The 464 has the broader forging temperature range of the two alloys . A watering can , slack tub or squirt bottle can help to control the heat by selectively cooling thinner sections of the work.
The naval bronze will mig weld, but not as well as the silicon ,but both work with Si wire, a good preheat and a He/ Argon/CO2 gas mix. Tig welding with He ,brazing or silver soldering or mechanical joinery are probably better options
The material is really expensive ,but in the right application, it is worth it. I find it better to buy an alloy with known properties from a reliable supplier . Dealing with scrap material can range from being simply frustrating to deadly toxic.
I've only been able to find 655 and 464 in round bar and plate. The last bronze project I did required a lot of flat bar of various widths so I bought a 4'x8'x1/4'' plate of 464 Naval Bronze and cut it up on a heavy duty table saw with a special thin kerf blade with no hook to the teeth. It was a really loud operation with nasty sharp [ and expensive] chips!

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While I have not forged brass successfully, I have however, forged silicon bronze with excellent results. To those who have not forged bronze, there is a narrow range of malleability. Note than when founding (melting) brass has a higher tendency to want to separate without sufficient flux than does bronze.

A common mistake is to constantly try different materials, including exotic and expensive metals. My suggestion is to first get good at the basics: forging techniques, hammering, fire, planning, etc. before wasting time and money on metals other than basic iron. Some of the really exotic materials (tool steels, for example) have so narrow a forging (mechanical working) range, that success only comes after much, much experience, patience and attention to detail. As the other fellows have noted, some of the gases produced from working 'other' materials can be harmful if not lethal. Mistakes of that nature are not habit forming.

Frankly, I would save the brass in a pail, then take it to the scrap dealer to buy good silicon bronze or lots of steel.

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