6063 is an aluminum-magnesium-silicon heat-treatable alloy and is one of the most popular alloys in the 6000 series. Mostly used in extruded architectural shapes, electrical components and conduit, and seamless and structural tube and pipe, 6063 aluminum is produced with extremely smooth surfaces that make it easier to anodize. It also has excellent resistance to corrosion, particularly stress-corrosion cracking. Alloy 6063 is fairly easy to machine and is highly weldable. After welding, the material may soften and lose strength at the connection, but a post-weld heat treatment can be applied to restore strength and hardness.