Design and structural engineering

ISO 13920 tolerances

The standard provides general tolerances for weldments using four classes for linear/angular dimensions and four classes for shape/position. Class selection follows function, not a desire for “maximum precision”, and applies only where the drawing does not state an individual requirement.

Open interactive module →

Topic overview

The standard provides general tolerances for weldments using four classes for linear/angular dimensions and four classes for shape/position. Class selection follows function, not a desire for “maximum precision”, and applies only where the drawing does not state an individual requirement.

Are the selected classes functionally justified, achievable by the fabrication process and unambiguously measurable in a defined product condition?

The actual limit is read from the table for the class and dimensional range.

Assembly- or safety-critical features need individual tolerances.

What the module covers

  • Weldment tolerances according to EN ISO 13920:2023
  • 1. Tolerance-class logic
  • 2. Practical use of EN ISO 13920:2023
  • 3. Typical conflicts
  • Drawing and inspection checklist
  • Practical rule
Educational content does not replace current standards, approved WPS/WPQR documentation or decisions by competent welding coordination personnel.