How do you tell red brass from yellow brass?

The percentages of copper and zinc in the alloy.

hit it with a grinder red brass puts out a red spark yellow brass puts out a yellow spark

Brass is an alloy of copper and zinc, and it may contain very small amounts of other metals such as lead and tin. Red brass is an alloy which typically contains 85% copper, 5% tin, 5% lead, and 5%...

Piping which is 40% Zinc and 60% copper

It s honey gold actually so closer to yellow