6061 Structural Aluminum 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 workability, 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. 6061-T6 American Standard Aluminum Angle Leg Length (1): 1.5 inch Leg Length (2): 1.5 inch Thickness: 0.250 inch Length: 18 inches Standard Tolerances, Tapered, Rounded Legs on inside of angle.