The pipes are made of copper.

A reddish-brown metal that is a good conductor of electricity and heat.
She bought a copper pot for cooking.
The statue is made of copper.
He found a piece of copper in the ground.
copper wire
copper pipe
copper alloy
metal
element
conductive material
The wires are made of copper.

A reddish-brown metal used in electrical wiring and plumbing.
The plumbing pipes are made of copper.
She bought a copper pot for cooking.
Copper is a good conductor of electricity.
copper wire
copper pipe
copper alloy
cuprum
metal
conductive metal