Overview
EN ISO 286-2:2010 (ISO 286-2:2010) is part of the Geometrical Product Specifications (GPS) family and provides the ISO code system for tolerances on linear sizes - Part 2: Tables of standard tolerance classes and limit deviations for holes and shafts. The document lists the upper and lower limit deviations (ES/EI for holes, es/ei for shafts) and the standard tolerance grades used for commonly applied fits. It applies to features that are cylinders or two parallel opposite surfaces (for example, diameters, slot widths, key thicknesses) and supports interchangeability and fit specification in mechanical design and manufacturing.
Key topics and requirements
- Limit deviations and tolerance classes: Tables (Tables 2–32) provide values for upper and lower limit deviations for standard tolerance classes; Table 1 gives standard tolerance grades IT01 to IT18.
- Feature types covered: Cylindrical features and two parallel opposite surfaces - the standard's tolerance/deviation values apply equally to non-circular sections where appropriate.
- Designation and symbols: Uses the standard hole/shaft notation (ES/EI for holes; es/ei for shafts); JS/js classes are symmetrical about zero.
- Calculation and presentation: Values are calculated from ISO 286-1 tables; clause 6 allows calculation of values for classes not explicitly tabulated.
- Selection guidance: The standard provides synoptic representations of classes (figures) but defers detailed selection recommendations to ISO 286-1 (selection of tolerance classes and fit function).
- Form and functional notes: ISO 14405-1 changes the default association criterion to the two-point size criterion; in many cases diameter tolerances alone may be insufficient - envelope criterion, geometrical form tolerances, or surface texture may be required to ensure intended fit function.
- Range limitations: Some tolerance classes are provided only for restricted nominal-size ranges; users should consult the specific tables and footnotes.
Applications and users
EN ISO 286-2:2010 is used by:
- Mechanical and design engineers specifying fits (clearance, transition, interference) on engineering drawings
- Manufacturing engineers and machinists for setting production tolerances
- Quality control and metrology personnel for inspection limits and acceptance criteria
- CAD/CAM and PLM teams for embedding standardized tolerance classes into part models
- Procurement teams and standards bodies for ensuring interchangeability of mass-produced parts
Practical uses include specifying hole/shaft fits, selecting tolerance grades for bearings, shafts, pins, and keys, and ensuring consistent communication of size tolerances across suppliers.
Related standards
- ISO 286-1:2010 - Basis of tolerances, deviations and fits (normative reference)
- ISO 14405-1 - Size specification (association criteria)
- Other GPS standards for form, position and surface texture when diameter tolerancing is not sufficient
Keywords: EN ISO 286-2:2010, ISO 286-2, tolerances on linear sizes, limit deviations, holes and shafts, tolerance classes, IT grades, Geometrical Product Specifications (GPS).
