Overview
EN ISO 6413:2018 - Technical product documentation - Representation of splines and serrations (ISO 6413:2018) is a CEN-adopted ISO standard that specifies rules and graphical symbols for showing splines and serrations in technical product documentation. It defines two permitted methods of representation - complete representation and simplified representation - and applies to detail drawings (shafts and hubs) and assembly drawings of spline/serration joints.
Key topics and requirements
- Scope and purpose
- Rules for depicting splines, serrations, straight-sided splines and involute splines in drawings to ensure uniform, unambiguous documentation.
- Two representation methods
- Complete representation: full tooth geometry with true dimensions - used only when necessary; follows general drawing rules (ISO 128-24).
- Simplified representation: preferred for efficiency; parts are shown as solid with additional lines indicating the root surface or pitch surface rather than each tooth.
- Graphical symbols and designation
- Specific symbols indicate the spline type (straight-sided, involute, serration). Proportions/dimensions of these symbols are given in Annex A.
- Designation text should be placed near the feature and connected to the contour by a leader line. If a spline deviates from the standard form, required data must be tabulated and cross-referenced.
- Detail representation rules
- For simplified drawings, represent parts as solid bodies and add:
- a continuous narrow line for the root surface (ISO 128-24 line type 01.1), or
- a long-dashed dotted narrow line for the pitch surface (ISO 128-24 line type 04.1).
- Projection note
- Figures are shown in first-angle projection for uniformity; third-angle projection is equally acceptable without changing the underlying principles.
- Normative references
Applications
- Streamlines creation of mechanical drawings and CAD documentation involving shafts, hubs, and mating joints.
- Reduces drawing complexity where full tooth detail is unnecessary - speeding up drafting, review, and manufacturing handoffs.
- Ensures consistent interpretation across design, manufacturing and quality control teams.
Who uses this standard
- Mechanical design engineers and drafters
- CAD technicians and technical illustrators
- Manufacturing engineers and quality inspectors
- Standards managers and technical authors producing product documentation
Related standards
- ISO 128-24:2014 - Technical drawings: lines on mechanical engineering drawings
- ISO 3098-2 - Technical product documentation: lettering (Latin alphabet, numerals)
Keywords: EN ISO 6413:2018, representation of splines and serrations, technical product documentation, splines, serrations, straight-sided spline, involute spline, graphical symbols, simplified representation, ISO 128-24.