This is southern yellow pine at its finest! 1 inch copper pipe! 4 x 6 beams! Interlocking 2 x 6 boards! End result customer was astonished! This pergola was constructed using methods never used today except by me. All of the intersecting joints use mortise and tenon joinery. All of the copper pipes are recessed into holes. Some of the mortise and tenon joints are double bypass. That of course probably doesn't mean much to the average reader. But if you are a woodworker you know exactly what I'm talking about and you understand the difficulty of assembly. I also challenged myself on this one by constructing it from some very simple drawings and no real plans. It was all done in my head! If you think that I'm bragging it's only because I am!