6061 Structural Aluminum Equal Leg Angle has round corners on inside of the angle, it provides higher strength and is commonly used in structural applications as the name suggest. 6061 is one of the most common alloys of aluminum in use today. It combines workabilty, weldability, and corrosion resistance into one alloy with medium strength. Can be used for all types of applications. T6 is the most common temper available and offers good strength.