Double hole hydraulic hollow screws with hex head and oil return pipe hinge joints are professional hydraulic connection fasteners widely used in construction machinery, automotive hydraulic systems, hydraulic equipment, pipeline assembly and mechanical maintenance industries. Made of high-strength carbon steel with professional surface treatment, these hollow hinge bolts feature double hole hollow structure, good sealing performance and stable connection effect, specially designed for oil return pipeline and hydraulic transmission systems. The standard hex head ensures easy installation and firm fastening, and precision machined threads guarantee tight fit and reliable use in hydraulic working environments. With reliable quality and strong practicability, these hydraulic hollow hinge joint screws are ideal for global hardware importers, hydraulic parts manufacturers and mechanical enterprises, providing professional and stable connection solutions for international industrial hydraulic projects.