ISO 13920-2023 PDF

Full title and description

ISO 13920:2023 — Welding — General tolerances for welded constructions — Dimensions for lengths and angles, shape and position. This international standard specifies general workshop-level tolerances and tolerance classes for linear and angular dimensions and for the shape and position of welded structures, to be used where individual tolerances are not specified on drawings.

Abstract

This document specifies general tolerances for linear and angular dimensions and for shape and position of welded structures in four tolerance classes, based on customary workshop accuracy. The main criterion for selection of a particular tolerance class is the functional requirements to be met. The standard applies to weldments, welding assemblies and welded structures; tolerances given in drawings take precedence, and special provisions may be necessary for complex structures. The specifications follow the independency principle of ISO 8015 (dimensional and geometrical tolerances apply independently).

General information

• Status: Published
• Publication date: June 2, 2023
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 17.040.10 (Limits and fits), 25.160.10 (Welding processes)
• Edition / version: Edition 2 (2023)
• Number of pages: 8

Scope

ISO 13920:2023 provides general tolerances for linear and angular dimensions and for the shape and position (straightness, flatness, parallelism and related form/orientation features) of welded constructions. It defines four tolerance classes based on customary workshop accuracy and is intended for use where drawings do not specify individual tolerances. The standard is applicable to weldments, welded assemblies and complete welded structures; it is not intended to replace specific functional tolerances or to cover special requirements for unusually complex assemblies.

Key topics and requirements

• Definition of four general tolerance classes for welded constructions (selection based on functional requirements).
• General tolerances for linear dimensions and angular dimensions.
• Tolerances and guidance for shape and position: straightness, flatness, parallelism and related features.
• Requirement that applicable tolerances are those shown on the drawing; the standard provides default classes where individual tolerances are not given.
• Application of the independency principle (ISO 8015) — dimensional and geometrical tolerances apply independently.
• Guidance that special provisions may be necessary for complex structures and that manufacturing documentation without adequate tolerance reference is incomplete.
• References to geometrical product specification (GPS) practice and measurement/inspection considerations.

Typical use and users

Used by designers, welding engineers, fabrication and assembly engineers, quality and inspection personnel, drafters and purchasing/procurement teams who specify or verify dimensional and geometric tolerances for welded constructions. Commonly applied in steel construction, structural and mechanical fabrication, shipbuilding, rail and vehicle manufacture, cranes and heavy equipment where consistent, workshop-level general tolerances are required.

Related standards

Closely related documents include ISO 8015 (Fundamental tolerancing principle / independency), GPS/Geometrical Product Specification standards such as ISO 1101 (geometrical tolerancing), and other welding and quality standards (for example ISO 3834 series on quality requirements for fusion welding). ISO 13920 is also used alongside general tolerance standards (e.g., ISO 2768) and standards covering measurement equipment and procedures referenced for inspection.

Keywords

welding; welded constructions; general tolerances; tolerance classes; linear dimensions; angular dimensions; straightness; flatness; parallelism; fabrication; assembly; ISO 13920; geometric tolerancing; workshop tolerances

FAQ

Q: What is this standard?

A: ISO 13920:2023 is an international standard that specifies general tolerances for dimensions, shape and position for welded constructions, providing four workshop-based tolerance classes to be used where individual tolerances are not indicated on drawings.

Q: What does it cover?

A: It covers tolerances for linear and angular dimensions and for shape and position (straightness, flatness, parallelism and related geometrical features) of weldments, welding assemblies and welded structures, and guidance on application of those tolerances in drawings and manufacturing documentation.

Q: Who typically uses it?

A: Designers, welding and fabrication engineers, quality/inspection personnel, drafters and procurement teams in industries that fabricate welded structures (steelwork, shipbuilding, rail/vehicle manufacture, cranes and heavy equipment).

Q: Is it current or superseded?

A: ISO 13920:2023 is the current edition (published June 2, 2023). It supersedes ISO 13920:1996.

Q: Is it part of a series?

A: It is a standalone international standard on general tolerances for welded constructions, but it is used in the context of broader GPS (geometrical product specification) practice and alongside other welding and quality standards (for example ISO 8015, ISO 1101 and the ISO 3834 series).

Q: What are the key keywords?

A: Welding, welded constructions, general tolerances, tolerance classes, dimensional tolerancing, geometric tolerancing, straightness, flatness, parallelism.