Brass and Copper alloys

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blaksdc

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Oct 10, 2019
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As you may know, there are a lot of different alloys that go under the name of brass and copper. I have found a site that sells pretty cheap rods and tubes of those materials, but I'm not sure if they are good for knifemaking. I'd like to know if any of you have experience with these alloys and can tell me if they are usable for pins/guards, or for food/kitchen utensils. I hope this thread may become useful for other people too.

COPPER

-CW004A (Cu-ETP): 99.90 Cu | 0.0005 Bi | 0.04 O | 0.005 Pb.
Is lead low enough for it to be usable?

-CW024A (Cu-DHP): 99.9 Cu | 0.015-0.040 P.
This one looks pretty safe.

BRASS

-CW508L (CuZn37): 62-64 Cu | <0.05 Al | <0.01 Fe, Pb, Sn each | <0.03 Ni | rest is Zn.
I know for sure a knifemaking supplies site in europe uses this kind of brass for rods and sheets.

-CW614N (CuZn39Pb3): 57-59 Cu | Similar to above BUT 2.5-3.5 Pb.
In this one the lead looks extremely higher, but the manifacturer told me it's used for faucets and such, so I'm not sure what to think.

-CW618N (CuZn40Pb2Al): Similar to above with slightly more Al (up to 0.5%).

Sorry if it's a weird or annoying question, as it's kind of technical, but I'd like to know a bit more before buying any of this.
 
To be called copper it is is 99% Cu and 1% other things. The Pb in the mix is fine for knife use. The Cu/P formula is the one I use most often.

Brass/bronze are many formulae depending on the use. There are free machining brass/bronze, Naval brass/bronze, etc. I like Phosphorous bronze, free machining yellow brass, and white brass (nickel silver) for knife use. Aluminum bronze is OK, too.
 
Thanks for the answer!
I've seen that free machining yellow brass has a "high" lead component, up to 3%, similar to the ones I posted. I'd have thought that it would have been too much, thinking about skin and food contact. I learned something new today, thanks again!
 
If you mill or grind the brass, you will find out why the free machining type is popular.
 
Lead is added to a lot of metals to make them easier to machine, but is in a state that's fairly safe to people when processed as intended. Just like the Cu alloy you noted above for plumbing fixtures, 12L14 and 41L40 are very common leaded steel alloys for the same purpose - ease of machining.

It only becomes a problem when the lead becomes an airborne dust & we breathe it in (grinding dust). On the other hand, most metals are very toxic to people when we breathe in the dust....
 
I’m a big fan of the silicon bronze alloys.
 
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