The spring specifications are as follows, could you predict the service life of the spring when installed and when operated under dynamic load? Is there a big difference between the coil part and the hook part?
Material SWPB
Wire diameter 2.3 mm
Coil average diameter 19 mm
Total number of coils 17
Free length 77 mm
Hook shape: U hook
Hooks’ inner diameter 12 mm
Inner hook rising part R4mm
Length when installed 82 mm
Operating length 117 mm
Initial tension about 12N
Thank you for your post, Yasu!
The expected service life of the above spring is about 10 million times! (For both the coil and hook parts)
* Bending stress is generated in the raised part of the hook, and torsional stress is generated in the coil parts. (Usually, the bending stress of the hook part has the greatest effect on the service life of the extension springs.)
