Other materials available for use as conduit fittings include aluminum, fiberglass, PVC, PVC coated aluminum or steel, nylon, polyester, urethane; or regular, galvanized, or stainless steel.
Tubing can be flexible or rigid depending on the material type and its intended purpose, though tubing listed in this product area is generally smaller and less rigid than materials classified as hose ...
PVC and CPVC, PEX, ABS, galvanized steel and cast iron — can mostly all be connected to each other with appropriate fittings.