The SS Heavy Duty Hinges are made of 304 stainless steel, measuring 100mm high, 68mm wide, and 3mm thick. They feature a 12mm edge margin, a 5.1mm diameter hole, and evenly distributed screw holes. The hinge axis has a 20mm diameter and features a built-in high-strength rebound spring, enabling automatic closing within a 90° range. A reinforcement at the axis ensures stable and smooth opening and closing even under long-term loads. They are suitable for applications requiring high durability and load-bearing capacity, such as public buildings, fire doors, and heavy metal doors.