UNE-EN 13906-3:2014 Cylindrical helical springs made from round wire and bar - Calculation and design - Part 3: Torsion springs (Endorsed by AENOR in March of 2014.)
2014UNE-EN 13906-3:2014 Cylindrical helical springs made from round wire and bar - Calculation and design - Part 3: Torsion springs (Endorsed by AENOR in March of 2014.)