NEN EN 13906-1 : 2013

1 Scope
2 Normative references
3 Terms, definitions, symbols, units and abbreviated
   terms
   3.1 Terms and definitions
   3.2 Symbols, units and abbreviated terms
4 Theoretical compression spring diagram
5 Design principles
6 Types of Loading
   6.1 Static and/or quasi-static loading
   6.2 Dynamic loading
   6.3 Operating temperature
   6.4 Transverse loading
   6.5 Buckling
   6.6 Impact loading
   6.7 Other factors
7 Stress correction factor k
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 Minimum permissible spring length
   9.10 Solid length
   9.11 Increase of outside diameter of the spring when
        loaded
   9.12 Fundamental frequency
   9.13 Transverse loading
   9.14 Buckling
   9.15 Impact stress
10 Permissible torsional stresses
   10.1 Permissible torsional stress at solid length
   10.2 Permissible torsional stress under static or
        quasi-static loading
   10.3 Permissible stress range under dynamic loading
Annex A (informative) Examples of relaxation for cold
        coiled springs