Enclosed trailer and horse trailer manufacturers, which are fabricated from aluminum in particular, often have trouble with 3-piece rear door and ramp door hinge alignment.
It takes a precise measurement and careful hands to align most standard 3-piece rear and ramp door hinges correctly due to the challenge of laying the hinge flat for welding or bolting. This can add an inordinate amount of time to the assembly process. Additionally, while most assemblers get close, even a slightly misaligned hinge can adversely affect its durability and longevity. These are two critical expectations for buyers of high-end aluminum trailers.