Power spring development for an industrial service reel

Industrial and automotive-service reels may handle air, water, electrical cable or other media. The spring must fit the assembly and match the reel’s operating travel, torque demand, end connections and environment.

Project specification

For one customer-drawing project covering a service-reel application, the recorded spring material was SUS301. The strip measured 0.45 mm thick, 30 mm wide and 9,000 mm long; the reported inner and outer diameters were 16 mm and 114 mm. The spring was checked against the assembly box.

Sample and inspection

Zongda completed a calculation and supplied a sample in one round. The project record states that the sample passed validation, that dimensional, hardness, torque and fatigue inspection was performed, and that an inspection report was available. The project entered mass production. Specific model mapping, test standard, operating conditions and production volume were not provided.

These dimensions are an example, not a general recommendation for every service reel. New projects should identify the reel type, medium, duty cycle, environment, drum and shaft dimensions, working turns and required torque. SUS301 provides better moisture and corrosion resistance than common carbon spring steels, but severe chemical or salt exposure still requires project-specific assessment.