The use of parallel fixed joints is common. Sometimes the leg of the aluminum tube workbench can not bear weight well by relying on one aluminum tube alone. At this time, the number of aluminum tubes can be increased by using this joint, so as to improve the bearing capacity of the workbench. Only one pair of screw and nut can easily fix two aluminum tubes. Aluminum items can be widely used in household, automobile, electronics, chemical industry, commercial logistics, flexible storage equipment, pharmacy, machine manufacturing.