Should I choose brass or copper fittings?
Choose brass for threaded fittings, valves, couplings and marine hardware: it is harder, machines cleanly and resists corrosion well. Choose copper where electrical or thermal conductivity matters, such as busbars, conductors and heat-exchange tube, or where the system is copper pipe joined by soldering or brazing.
| Brass (copper–zinc) | Copper | |
|---|---|---|
| Hardness and strength | Harder and stronger | Softer, more ductile |
| Machining and threads | Excellent, especially free-cutting grades | Gummy to machine |
| Electrical conductivity | Lower (roughly a quarter to a third of copper) | Highest of common metals (about 100% IACS for Cu-ETP) |
| Corrosion | Good; choose dezincification-resistant grades for some waters | Good; forms a protective patina |
| Typical uses | Valves, couplings, fittings, marine hardware | Busbars, wire, tube, earthing |
Marine use
Brass is the usual material for fire hose couplings and scupper plugs because it resists sea air and does not spark. For fittings permanently immersed in seawater, bronze or dezincification-resistant brass is often specified.