ISO 6761-1981 PDF

Full title and description

Steel tubes — Preparation of ends of tubes and fittings for welding. Specifies customary end preparations for butt welding of steel tubes and of tube fittings, gives graphical symbols, tabulates nominal thicknesses with their designations and symbols, shows typical forms of ends (illustrated) and gives key dimensions such as bevel angles and root-face widths.

Abstract

This International Standard specifies the most usual preparations for welding ends of steel tubes and of tube fittings. It provides standard symbols for end preparations, tables linking wall thicknesses to recommended designations and symbols, illustrative figures of end forms and the relevant dimensions (including bevel angles and root-face widths).

General information

• Status: Withdrawn.
• Publication date: October 1981 (Edition 1, 1981).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 23.040.10, 23.040.40 (steel tubes; tube fittings).
• Edition / version: Edition 1 (1981).
• Number of pages: 1 (ISO bibliographic record; some national distributors list expanded copies or presentation pages up to 4).

Scope

Applies to preparation of ends of steel tubes and of tube fittings intended to be joined by welding. The standard covers the common joint-preparation geometries used for butt welding, the graphic symbols used to denote these preparations on drawings, tabulated correspondence between nominal wall thicknesses and designation symbols, and the principal dimensions required for correct weld preparation (for example bevel angles and root-face widths). It is focused on geometry and representation rather than on welding procedure, filler materials or qualification of welders.

Key topics and requirements

• Standardized end-preparation types for buttweld joints (square cut, plain bevel, compound bevel, etc.).
• Graphical symbols for indicating end-preparation types on drawings.
• Tables linking tube wall thickness ranges to recommended designations and symbols.
• Illustrative figures showing forms of ends and the key dimensions (bevel angle, root face width, land).
• Guidance is limited to geometrical preparation; it does not specify welding procedures, qualifications or filler materials.

Typical use and users

This standard is intended for designers, drawing offices and manufacturers of steel tubes and tube fittings, welding engineers and fabricators who prepare or specify weld-ready tube ends, and procurement/specification writers who need a concise, consistent way to denote end-preparation geometry on drawings and data sheets. It is used when specifying how tube ends should be cut and beveled before assembly and welding.

Related standards

Standards covering related topics include national and international documents that specify buttweld end dimensions and tolerances and requirements for fittings, for example ASME B16.25 (Buttwelding Ends) and ASME/ANSI and EN standards for buttweld fittings and piping; additional standards cover tube dimensions and tolerances and fittings (examples: ASME B16.9, EN/ISO series on tubes and fittings). These documents are commonly used together with ISO 6761-style guidance when producing welding and procurement specifications.

Keywords

steel tubes; tube fittings; end preparation; welding ends; bevel; root face; buttweld; drawing symbols; weld preparation.

FAQ

Q: What is this standard?

A: ISO 6761:1981 is an International Standard titled "Steel tubes — Preparation of ends of tubes and fittings for welding" that defines common weld-end preparations, symbols and key dimensions for steel tubes and tube fittings.

Q: What does it cover?

A: It covers the geometry and graphical representation of the most usual end preparations for butt welding of steel tubes and fittings, including tables of wall-thickness designations, symbols, illustrative figures of end forms and principal dimensions (bevel angles, root-face widths). It does not set welding procedure qualifications, materials or consumables.

Q: Who typically uses it?

A: Designers, drawing offices, tube and fitting manufacturers, welding engineers, fabricators and procurement/specification authors who need standardized end-preparation geometry and drawing symbols for buttweld joints.

Q: Is it current or superseded?

A: ISO 6761:1981 has been withdrawn and is no longer an active ISO publication. National catalogues and standards bodies list it as withdrawn (withdrawal actions recorded in ISO lifecycle notes and by national bodies during 2018–2019); it appears to have been withdrawn without a direct like-for-like replacement. Users should consult current national or industry documents for up-to-date end-preparation requirements (for example ASME B16.25 and current EN/ISO piping and fitting standards).

Q: Is it part of a series?

A: It was produced under ISO technical committee work on steel tubes (ISO/TC 5/SC 1). While not a numbered "series" in itself, it sits among numerous ISO publications dealing with tubes and fittings; related ISO and national standards address tube dimensions, tolerances and fittings.

Q: What are the key keywords?

A: Steel tubes, tube end preparation, buttweld, bevel, root face, welding symbols, tube fittings.