Flanges

Stainless steel, cast iron, aluminium, brass, bronze, plastic, and other materials are used to make pipe flanges, but forged carbon steel with machined surfaces is the most common.

Additionally, flanges, like fittings and pipes, are occasionally internally fitted with layers of materials that are of a completely different grade than the flanges themselves. These are known as "lined flanges," and they are used for specialised reasons.