NEN EN 13906-2 : 2013

Foreword
1 Scope
2 Normative references
3 Terms and definitions, symbols, units and abbreviated terms
   3.1 Terms and definitions
   3.2 Symbols, units and abbreviated terms
4 Theoretical extension spring diagram
5 Types of loading
   5.1 Static and/or quasi-static loading
   5.2 Dynamic loading
6 Stress correction factor k
7 Initial tension force F[o]
8 Material property values for the calculation of springs
9 Calculation formulae
   9.1 Spring work
   9.2 Spring Force
   9.3 Spring deflection
   9.4 Spring rate
   9.5 Torsional stresses
   9.6 Nominal diameter of wire or bar
   9.7 Number of active coils
   9.8 Total number of coils
   9.9 Initial tension force
10 Permissible torsional stress under static or quasi-static
   loading
   10.1 Permissible torsional stress Tau[zul] for cold coiled
        springs
   10.2 Permissible torsional stress Tau[zul] for hot coiled
        springs
   10.3 Initial tension torsional stress Tau[o]
11 Calculation of extension springs for dynamic loading
Annex A (informative) Types of spring ends

Describes the calculation and design of cold and hot coiled helical cylindrical helical extension springs made from round wire and bar loaded in the direction of the spring axis and operating at normal ambient temperatures.