Magnesium Bronze

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Stan

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ASTM B584 CDA 867. Anybody have experience with this stuff. I aquired four feet of 1.625" and wondering what I am going to use it for. Google shows some specialized uses, like top bushing in race engine conn rods, but no general info Note that this is not Manganese Bronze.
Analysis
Copper 55-60%
Lead max .5-1.5%
Aluminum 1.0-3.0%
Nickel max 1.0%
Zinc 30-38%
Manganese 1.0-3.5%
Tin max .2%
 
Stan said:
ASTM B584 CDA 867. Anybody have experience with this stuff. I aquired four feet of 1.625" and wondering what I am going to use it for. Google shows some specialized uses, like top bushing in race engine conn rods, but no general info Note that this is not Manganese Bronze.
Analysis
Copper 55-60%
Lead max .5-1.5%
Aluminum 1.0-3.0%
Nickel max 1.0%
Zinc 30-38%
Manganese 1.0-3.5%
Tin max .2%

I don't see any Magnesium listed in the above.
...lew...
 
It is not my fault there is no magnesium. That is the proper name and ASTM data. Bar is marked "Magnesium Bronze 867" presumably from the metal supplier. It appears from searching that a lot of large valves use magnesium bronze for the stem. My guess is that a machine shop was repairing some valves and charged the customer for the whole bar and then sent the remainder to the scrap metal (where I bought it).

The analysis is very different than manganese bronze, especially the tin which can be as high as 20% in manganese bronze.
 
Hi Stan,
The analysis of your bronze alloy is interesting, especially the high zinc content.
Coincidentally I just acquired 4 feet of 1.625" dia bronze from an ebay seller. It is C64200 Aluminum bronze. I did some research on this and found the "Anchor Bronze" website to be helpful. They give all sorts of characteristics (soldering, brazing, hardness etc). Turns out C64200, while not a bearing bronze (no lead in it for one thing) machines nicely, like cast iron without the graphite mess and is fairly hard. Makes nice model engine parts. It's also used in marine applications as many bronzes have good corrosion resistance.
Cheers,
Phil
 
It will make great bearing bushings or shaft support columns that won't require bearings.

Don't try to turn it to too thin a diameter. It will break like a half thawed icesickle. :D

Rick
 
Il second the remarks from Rick thin sections are a nightmare with the stuff.
It will get hot when machined and drilling will generate a lot of heat if your not careful.

I wish I could find deals on bar stock like you guys!

Cheers kevin
 
I'll vouch that the heat from drilling is substantial. I was drilling some of the aluminum bronze yesterday and since the stuff throws off chips like cast iron, I was cutting it dry. WRONG! :-[ I was drilling in 1/8" steps on the lathe and when I went to 1/2" I noticed some smoke from the surface oil. Then suddenly the whole workpiece turned a golden color and the bit seized. Luckily the drill chuck arbor let go and the chuck spun merrily away. After that I used lots of oil and drilled up to 3/4" without incident. Every new material is an adventure.

Cheers,
Phil
 
Phil: Thanks for the Anchor Bronze URL. They have the specs and call it a free machining bronze for valve stems and marine propellers. In one of my searches I found that the Titanic had 16' magnesium bronze propellers. Usefull information but not planning to make any.
 

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