the difference between brass and bronze

[savarin]

How can I tell the difference between some bronze and brass?
I have an old water pump housing and impeller that I'm thinking of casting some stock from but I would like to know if its brass or bronze.
Thanks.

 

[stevehuckss396]

Sometimes you can tell just by looking at it. Bronze will sometimes have a tiger stripe pattern on its skin where brass will a consistent color skin. Once the skin is machined off it gets harder to tell for me being color blind but with some experience you can sometimes tell by the third cut just by the way it machines.

 

[WOB]

Look here: https://www.practicalmachinist.com/vb/general/how-identify-brass-vs-bronze-179095/
Google has much more on the subject.

WOB

 

[john_reese]

Heat a small piece with an O/A torch. If it gives off white smoke after it melts it is brass. The smoke is the zinc burning out.

 

[savarin]

I think its bronze. This is some of it turned with the chips.
I guess as I will be melting it it doesnt really matter but I want to use it for a cross slide nut and am hoping it will work out ok.
If all goes well I will make some stock for future projects.

 

[Jack3M]

Bronze

 

[mohavegun]

Brass and Bronze depends on who is talking about which! generally brass is dominantly a copper and zinc alloy, bronze generally has something else in it in place of the zinc or mixed in with the zinc. Aluminum bronze is just that, copper & aluminum, silicon bronze and leaded bronze are other good examples... However, there are some brass alloys that contain Tin or other metals in place of zinc.

 

[Chiptosser]

When you are turning, bronze will chip, brass will not chip as readily. Brass can string or curl before breaking off.

 

[Charles Lamont]

That piece looks like gunmetal (unhelpfully known in the US as 'red brass'). The swarf look like leaded gunmetal. As it is from a pump it is likely to be gunmetal, or possibly bronze. As seen on my screen, it has a slightly pinkish tinge, which also points to gunmetal.
In my experience, most of the brass I have come across machines to a fine crumb that flies everywhere and gets itself into the socket of every cap-head bolt on the lathe.

 

[kquiggle]

Online Metals has good information on types of brass and bronze:

• The OnlineMetals Guide to Brass
• The OnlineMetals Guide to Bronze

Oddly, OnlineMetals also sells C353 engraver's brass, but their guide to brass does not mention it.

 

[Shopgeezer]

Brass and Bronze depends on who is talking about which! generally brass is dominantly a copper and zinc alloy, bronze generally has something else in it in place of the zinc or mixed in with the zinc. Aluminum bronze is just that, copper & aluminum, silicon bronze and leaded bronze are other good examples... However, there are some brass alloys that contain Tin or other metals in place of zinc.

Traditionally bronze is copper and tin. When we talk of the "Bronze Age" we mean the period when copper from various sources was alloyed with tin primarily from Britain. They were the hottest trade commodities of their day. Adding zinc to copper made Brass, but as stated you can add all kinds of things to copper and these days there are a lot of different alloys.

 

[Jennifer Edwards]

It has been my experience that the difference between brass and bronze is about ten pounds sterling