Widely used structural alloys for light to medium strength applications. Combine good formability, weldability, brazed with fine finishing characteristics and good corrosion resistance and strength after heat treatment. Since they lose appreciable strength when welded, the 5000 series alloys replace them in some marine applications. Availability of bars, shapes, tubing and pipe in the same alloy helps make this a popular selection. 6082 is the most common heat treated plate from stock. 6061 is similar to 6802 with better formability but more difficult to extrude and possessing lower strength. Used for couplings, hardware, hydraulic pistons, etc.