UNI ISO 3408-5 : 2009

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and subscripts
  4.1 Symbols
  4.2 Subscripts
5 Basic axial load ratings
  5.1 Basic static axial load rating, C[0a]
  5.2 Basic dynamic axial load rating, C[a]
6 Modified axial load ratings
  6.1 Modified static axial load rating, C[0am]
      6.1.1 General equation
      6.1.2 Correction for surface hardness, f[h0]
      6.1.3 Correction for accuracy, f[ac]
  6.2 Modified dynamic axial load rating, C[am]
      6.2.1 General equation
      6.2.2 Correction for surface hardness, f[h]
      6.2.3 Correction for accuracy, f[ac]
      6.2.4 Influence of material melting process, f[m]
7 Life
  7.1 Equivalent rotational speed and equivalent axial load
      7.1.1 General
      7.1.2 Ball screw with backlash between ball nut and
            screw shaft
      7.1.3 Ball screw with preloaded ball nuts on screw shaft
  7.2 Nominal life, L or L[h]
      7.2.1 Ball screw with backlash between ball nut and
            screw shaft
      7.2.2 Ball screw with preloaded ball nuts on screw shaft
      7.2.3 Resulting life, L[r]
      7.2.4 Nominal life, L[ar] or L[har], with reliability
            factor, f[ar]
  7.3 Modified life, L[m] or L[hm]
      7.3.1 Ball screw with backlash between ball nut and
            screw shaft
      7.3.2 Ball screw with preloaded ball nuts on screw shaft
      7.3.3 Modified resulting life, L[mr]
      7.3.4 Modified life, L[mar] or L[hmar], with reliability
            factor, f[ar]

ISO 3408-5:2006 specifies the calculation schemes for static and dynamic load ratings, and operational life, in order to obtain comparable values for the design and use of ball screws.