ISO 2538-2:2014

Overview

ISO 2538-2:2014 - Geometrical product specifications (GPS) - Wedges - Part 2: Dimensioning and tolerancing specifies methods for how wedges are to be dimensioned and toleranced on engineering drawings and in product specification systems. Although illustrations use truncated wedges for simplicity, the standard applies to any wedge geometry. It updates and replaces the previous ISO 2538:1998 and forms Part 2 of the ISO 2538 series.

Key topics and technical requirements

• Scope and intent: Defines methods for dimensioning and tolerancing wedge features so that design intent, manufacturing and inspection are consistent with GPS principles.
• Graphical symbol for slope: A standard graphical symbol and rules for indicating slopes (ratio or percent) on drawings, including orientation and leader/reference line practice.
• Dimensioning methods: Recommended characteristic combinations and typical dimensioning schemes:
  • Heights at larger/smaller ends (H, h), heights at cross-sections (Hx), lengths (L, Lx)
  • Thickness at larger/smaller ends (T, t), thickness at cross-sections (Tx)
  • Slope representations: wedge angle (β), slope rate (C), slope percent (S)
  • Rule: specify no more dimensions than necessary; auxiliary dimensions may be given in brackets.
• Tolerancing methods:
  • Use of geometrical tolerances (ISO 1101) for sloped features and overall wedge form.
  • Tolerance zone concept: zones limited by parallel planes that carry the wedge angle β; the letter t denotes the width of the tolerance zone.
  • Examples cover common cases: location of a side to its second face, sides without datum, wedge located or oriented from datums, and locating both sides from single or common datums.
  • Guidance when only dimensional tolerances are used: add geometrical tolerances per ISO 1101 if shape control is functionally required.
• Standards linkage: Recommends using the standardized series of wedges in ISO 2538‑1 when designing wedges; conforms to GPS rules (ISO 8015) and decision rules (ISO 14253‑1).

Applications and who uses it

• Practical for design engineers, drafting/CAD specialists, manufacturing engineers, metrology and quality-control professionals, and technical authors developing drawings and part specifications.
• Common applications:
  • Designing and specifying wedge-shaped machine elements, shims, fixtures and tooling
  • Preparing CAD models and engineering drawings with consistent slope and wedge tolerancing
  • Establishing inspection criteria and measurement procedures for sloped surfaces
  • Ensuring interchangeability and functional fit where wedge geometry affects assembly or performance

Related standards

• ISO 2538-1: Series of angles and slopes (preferred wedge series)
• ISO 1101: Geometrical tolerancing - form, orientation, location and run-out
• ISO 8015: Fundamental rules of GPS
• ISO TR 14638: GPS masterplan and matrix model
• ISO 14253-1: Decision rules for verification

Keywords: ISO 2538-2:2014, geometrical product specifications, GPS, wedges, dimensioning and tolerancing, wedge angle, slope symbol, ISO 1101, datum, tolerance zone.