Abstract: A hollow profile insert or key can be used to form structural joints. In forming the joint, the insert or key is inserted into open ends of two or more hollow members, where the members are hollow at least in the joint forming area. An adhesive is then applied to the interface between the insert or key and each hollow member. The insert is engineered with channels and recessed adhesive accumulation areas or adhesive pans such that the adhesive accumulates only at a location at the recessed area, in a bonding location with the member, providing significant structural integrity to the joint. The insert can be configured to include either an external hinge pin insert aperture that is configured to accept a hinge pin or a support wheel support wheel aperture and a support wheel located therein.