Cylindrical Drum Spring Assembly with Spiral Coil Spring Assembly and Integral Terminal Hook/Tab

Spiral coil spring assembly — also referred to as a clock spring, power spring, or constant-force spiral spring — wound from alloy steel flat strip to store and release rotational energy with a near-linear torque output per revolution of deflection. Unlike compression or extension springs that operate in translation, spiral coil spring assemblies deliver controlled torque through angular displacement, making them the primary energy storage element in retraction, counterbalance, and return-force mechanisms. The integral terminal hook and tab engage a mating arbor or anchor at defined deflection angles, with free length, strip width, strip thickness, and spring rate held to your drawing tolerances. Spiral coil spring assemblies are produced from high-carbon or alloy steel strip stock — commonly AISI 1074, 1095, or 301 stainless steel — selected based on fatigue life, operating temperature, and corrosion requirements. Strip is heat-treated to achieve the target hardness range (typically HRC 44-51 for carbon steel spring strip) before winding, ensuring consistent elastic properties over the rated cycle life. The close-wound coil is formed with controlled inter-coil friction characteristics — tighter winds increase close-out friction and damping, while open winds reduce friction for applications requiring free, low-hysteresis return. End terminations include formed hooks, punched tabs, riveted hubs, and clamped or hinged arbor mounts, configured to your assembly interface. Spiral coil spring assemblies serve a wide range of industrial and mechanical applications. Retractable cord and cable reels in vacuum cleaners, industrial cable hoists, and extension lead housings use spiral springs to provide the constant retraction pull that winds the cord back into the housing. Motor brush return assemblies in DC motors and generators rely on spiral springs to maintain consistent brush-to-commutator contact pressure throughout brush wear life. Counterbalance mechanisms in overhead doors, flip-up display panels, jet boarding stairs, and armoured vehicle hatches use spiral springs to offset dead weight and allow single-handed operation. Seatbelt retractors in automotive restraint systems use precisely calibrated spiral springs to maintain belt tension and enable smooth payout and retraction. Robotic joint return mechanisms and rotary actuator preloads use spiral springs where controlled torque in a compact radial envelope is required. IATF 16949, ISO 14000, and ISO 9001-certified production at Guangdong Huaersai Spring Industry's 8,000 m² Dongguan facility. First article and batch sampling verify free length, wire diameter, and hook geometry. Industries served include military, robotics, aerospace, medical equipment, and motorsport. Include free length tolerance, spring rate (torque per revolution), strip width, strip thickness, alloy steel grade, and end termination type in your RFQ for spiral coil spring assemblies from our Dongguan spring production facility.