ISO 2538-1:2014

Overview

ISO 2538-1:2014 - Geometrical product specifications (GPS) - Wedges - Part 1: Series of angles and slopes - defines standard terms, definitions and nominal values for wedges used in general mechanical engineering. The standard specifies three series of wedge angles (from 120° down to 0° 30′) and a series of wedge slopes (from 1:10 to 1:500), together with calculated quantities such as the rate of wedge. ISO 2538-1 is a general GPS document that establishes a common vocabulary and preferred value sets for wedge features; complementary standards cover dimensioning, tolerancing, measurement and calibration.

Key topics

• Definitions: precise meanings for wedge, wedge angle (β), wedge slope (S), rate of wedge (C), wedge edge, vee‑block and dovetail.
• Nominal values: three series of wedge angles and a slope series with recommended nominal values; a table of nominal and calculated values (angles, slopes and rates) is provided.
• Rate formula: the rate of wedge C is defined as C = 2 · tan(β/2).
• Usage guidance: Series 1 and 2 are to be used in order of preference to reduce the variety of tools, gauges and measuring instruments required for production.
• GPS matrix context: Annex A explains how ISO 2538‑1 fits into the GPS matrix, influencing chain links 1 and 2 for angle standards and referring users to ISO 8015 and ISO 14253‑1 decision rules.

Applications

ISO 2538-1 is practical for anyone specifying, producing or inspecting wedge-shaped features:

• Design engineers selecting standard wedge angles or slopes for mechanical parts (e.g., vee‑blocks, dovetails).
• Tooling and fixture designers who need standardized wedge geometries to minimize tooling variants.
• Metrology and quality engineers who reference nominal values when creating inspection plans or calibrating gauges.
• Manufacturers producing components with angular features where adherence to GPS improves interchangeability and conformity.

Practical uses include specifying wedge geometry on drawings, selecting stock angles for jigs, defining inspection references, and aligning measurement procedures with GPS principles.

Related standards

• ISO 2538-2 (Dimensioning and tolerancing for wedges)
• ISO 8015 (GPS fundamentals)
• ISO 14253-1 (Decision rules for conformity by measurement)
• ISO/TR 14638 (GPS Masterplan)

Keywords: ISO 2538-1, wedge angles, wedge slopes, geometrical product specifications, GPS, vee-block, dovetail, mechanical engineering, wedge rate, metrology.