I have a question about torsion coil springs. In JIS, the standard center values of “free angle” and “specified twist angle, planned twist angle” are different. The free angle is specified by Af. The twist angle is A1 and A2. The planned twist angle is W1. Is there any reason for this difference?
Thank you for writing to us, Kashimashi! The drawings we received are written according to two standards. Basically, it seems that it is based on the idea of the person who designed it, but from the production side, it is usually written like Af ° due to product measurement. Regarding the reference from the center, it represents the angle at which the torsion spring actually functions, but it cannot be measured. It is often the case that you write them separately depending on the actual usage!
