We are currently looking for a 28(5ft dove) gooseneck flatbed for general farm use and an occasional collector tractor. 14k-20k range trailer Every trailer I see sold today has a 12" i-beam frame and neck, but a trailer I borrowed yesterday is built on a rec. tube frame, including the neck (6x8 I believe not sure on the thickness). The trailer seems to be well built with 3 or 4 crossmembers in the frame and it also has tube crossmember under the deck on 16 inch centers. This trailer has 10k pound tandem axles. I was just wondering what size the tubing has to be to compare to the standard i-beam construction. I pulls nice and may be for sale but I wanted to ask the experts before considering a purchase. So what is the strength differences, advantages or disadvantages of I-beam vs. tube? TIA