Composition
Red brass is composed of approximately 85 percent copper and 15 percent zinc, along with minuscule traces of lead and tin. The reddish tint is due to the high volume of copper, hence the name.
Yellow brass usually contains 60 or 70 percent copper and 30 to 40 percent zinc, with trace amounts of lead and tin.
Uses
Yellow brass is the most commonly used of any brass. Most household plumbing uses yellow brass, as well as the automobile industry, which uses it for antennas, connectors, radiators among other items. Most keys are also made of yellow brass.
Red brass brass is much less common and can be found in shut-off values, sprinkler heads and other flexible water pipelines. Many other random objects and instrument also use red brass, including jewelry.
Recycling
Both yellow and red brass scraps are highly in demand and priced accordingly. Brass scraps are important to the brass and bronze industries, as the scraps are often used for kitchen and house remodeling, among many other uses.
Red brass scraps that often get recycled include valves, machine bearings and any other red brass scrap with a high percentage of copper.
Older yellow brass that gets recycled most of the time includes plated materials, rods and castings, brass sheets and tubing. It must be free of manganese bronze and aluminum bronze to be recycled.