Steel angle, also named angle iron, or steel angle bar, is basically manufactured by hot-rolled carbon steel or high strength low alloy steel. It has L-cross shaped section with two legs - equal or unequal and the angle would be 90 degree.
6061-T6 Aluminum Angle, aka Structural Aluminum Angle is an extruded aluminum product with inside radius corners that is intended for all structural applications where greater strength is required. 6061 Aluminum Angle is widely used for all types of fabrication projects where lightweight and corrosion resistance is a concern - frame work, braces, supports, trailers, truck beds, etc.
304/304L Stainless Angle, is a hot rolled stainless angle shape with inside radius corners that is ideal for all structural applications where greater strength and superior corrosion resistance is required.