Overview
ISO 286-2:2010 is part of the international GPS (Geometrical Product Specifications) framework and provides the definitive tables of standard tolerance classes and limit deviations for holes and shafts. It gives the values of upper and lower limit deviations (ES/EI for holes and es/ei for shafts) calculated from the basis in ISO 286-1. The standard applies to linear sizes for features of the cylinder type (e.g., diameters) and to two parallel opposite surfaces (e.g., slot widths or key thicknesses), and its tolerances equally apply to non‑circular sections.
Key topics and technical requirements
- ISO code system for tolerances on linear sizes: Uses standardized tolerance grades (IT01 to IT18) and coded fundamental deviations for holes and shafts.
- Limit deviations: Provides tabulated values for upper and lower deviations - ES / EI (holes) and es / ei (shafts) - for commonly used tolerance classes.
- Feature types covered: Cylinders and two parallel opposite surfaces (explicitly referenced), with clear statement that values also apply to other cross-sections.
- Nominal-size precondition for fits: The hole and shaft forming a fit must have the same nominal size for the code system to be applied.
- Tables and presentation: Tables 2–32 present deviations across nominal size ranges; Table 1 contains standard tolerance grade (IT) values derived from ISO 286‑1.
- Guidance on selection: ISO 286‑2 supplies the numerical data; selection recommendations are given in ISO 286‑1 (basis of tolerances, deviations and fits).
- Informative annexes: Annex A offers graphical review of tolerance intervals; Annex B explains the relationship to the GPS matrix model.
- Compatibility note: Interaction with measurement association criteria (e.g., envelope vs two‑point size) is addressed in related GPS standards such as ISO 14405‑1.
Practical applications and who uses it
- Mechanical design engineers specifying fits between mating parts (clearance, transition, interference).
- Manufacturing engineers and machinists for process planning, setting machining and inspection tolerances.
- Quality, metrology and inspection teams to interpret limit deviations for pass/fail decisions.
- CAD/CAM and tooling professionals implementing standardized tolerance classes into drawings, models and toolpaths.
- Supply chain and procurement for ensuring interchangeability of mass‑produced components.
Practical uses include specifying shaft/hole fits in bearings, fasteners, shafts, pins, mating bores, keys, and slots where standardized tolerances ensure interchangeability and predictable assembly behaviour.
Related standards
- ISO 286-1:2010 - Basis of tolerances, deviations and fits (required companion document).
- ISO 14405-1 - Size specification and association criteria (relevant to form/size interpretation).
- Other GPS standards for form, orientation and surface texture may be used alongside ISO 286‑2 for complete functional control.
Keywords: ISO 286-2, ISO code system, tolerances on linear sizes, limit deviations, holes and shafts, GPS, standard tolerance classes, IT grades, fits, interchangeability.