EN ISO 20168:2021

Resistance welding - Locking tapers for electrode holders and electrode caps (ISO 20168:2016)

ISO 20168:2016 specifies the dimensions and tolerances for electrode holders and of spot welding electrode caps, where a locking taper is used.

Widerstandsschweißen - Selbsthemmende Kegel für Elektrodenhalter und Elektronenkappe (ISO 20168:2016)

Dieses Dokument legt Maße und Grenzabweichungen für Elektrodenhalter und Punktschweiß-Elektrodenkappen fest, bei denen ein selbsthemmender Kegel verwendet wird.

Soudage par résistance - Cônes de serrage pour porte-électrodes et pointes d'électrodes (ISO 20168:2016)

L'ISO 20168:2016 spécifie les dimensions et les tolérances pour les porte-électrodes et les pointes d'électrodes pour soudage par points, lorsqu'un cône de serrage est utilisé.

Uporovno varjenje - Samozaporni strožci za elektrodna držala in kape (ISO 20168:2016)

General Information

• Status: Published
• Publication Date: 12-Jan-2021
• Withdrawal Date: 30-Jul-2021
• ICS: 25.160.20 - Welding consumables
• Technical Committee: CEN/TC 121 - Welding
• Drafting Committee: CEN/TC 121 - Welding
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 13-Jan-2021
• Due Date: 16-Jul-2022
• Completion Date: 13-Jan-2021
• Ref Project: SIST EN ISO 20168:2021 - Resistance welding - Locking tapers for electrode holders and electrode caps (ISO 20168:2016)

Overview

EN ISO 20168:2021 is a European and international standard that specifies the precise dimensions and tolerances for locking tapers used in electrode holders and spot welding electrode caps in resistance welding applications. Originally published as ISO 20168:2016, this standard ensures compatibility and interchangeability between electrode components by defining strict geometric criteria for the locking taper connection. The standard is essential for manufacturers, engineers, and quality assurance professionals within the welding industry to maintain consistency, reliability, and safety in resistance welding equipment.

Key Topics

• Scope and Purpose
  EN ISO 20168:2021 covers the exact dimensions and permissible tolerances required for electrode holders and spot welding electrode caps that utilize a locking taper-traditionally known as a “Fisher taper.” This locking taper ensures a secure, tight fit which improves electrical contact and mechanical stability during welding.

• Dimensional Specifications

  • The taper angle for electrode holders is fixed at 2° 58ʹ 54ʺ.
  • The taper angle for electrode caps is slightly less at 2° 56ʹ 53ʺ, guaranteeing a locking effect by taper angle mismatch.
  • Dimensions for three common nominal sizes of electrode caps and holders are defined: 13 mm, 16 mm, and 20 mm.
  • Verification methods including the use of certified ring gauges and plugs are prescribed to ensure adherence to these dimensions.

• Designation and Marking

  • Electrode holders and caps must be designated clearly using the standard’s format, which includes nominal diameters and type codes.
  • Markings on packaging must include the full standard designation and material information compliant with related standards.

• Material Requirements
  Materials used for these components must conform to ISO 5182, covering welding electrode materials and ancillary equipment to maintain performance and durability.

• Key Terminology

  • Locking taper: A taper connection that ensures increasing tightness between electrode holder and cap during use.
  • Tolerance: Permissible variations in dimensions to allow consistent manufacturing without compromising fit or function.

Applications

• Resistance Welding Equipment
  The standard is primarily applied by manufacturers and users of resistance welding machinery. It ensures electrodes and holders fit securely, enabling optimal electrical conductivity and mechanical stability during the welding process.

• Quality Assurance and Compliance
  Welding consumables manufacturers rely on EN ISO 20168 to meet international quality and safety standards. Proper taper dimensions help prevent electrode loosening or misalignment, reducing welding defects and downtime.

• Interchangeability of Components
  Standardizing taper dimensions allows for the interchange of electrode holders and caps from different suppliers, simplifying maintenance and reducing equipment downtime.

• Industrial Sectors
  This standard supports automotive manufacturing, electrical component assembly, and metal fabricating industries where spot welding is extensively used.

Related Standards

• ISO 5182 - Resistance welding materials for electrodes and ancillary equipment, detailing criteria for materials used in electrode holders and caps.
• ISO 5821 - Spot welding electrode caps, describing classification and designation of electrode caps, used alongside EN ISO 20168 for full product specification.
• ISO 17677-1 - Resistance welding vocabulary, offering terminology related to spot, projection, and seam welding; ensures consistent communication in specification and practice.
• ISO 5822 - Spot welding equipment – gauges used to verify taper dimensions in electrode caps and holders.

By adherence to EN ISO 20168:2021, manufacturers and end-users maintain compatibility and high-quality welding performance, promoting safety, efficiency, and reliability in resistance welding operations across global markets.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2021
Uporovno varjenje - Samozaporni strožci za elektrodna držala in kape (ISO
20168:2016)
Resistance welding - Locking tapers for electrode holders and electrode caps (ISO
20168:2016)
Widerstandsschweißen - Selbsthemmende Kegel für Elektrodenhalter und
Elektronenkappe (ISO 20168:2016)
Soudage par résistance - Cônes de serrage pour porte-électrodes et pointes
d'électrodes (ISO 20168:2016)
Ta slovenski standard je istoveten z: EN ISO 20168:2021
ICS:
25.160.20 Potrošni material pri varjenju Welding consumables
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 20168
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2021
EUROPÄISCHE NORM
ICS 25.160.20
English Version
Resistance welding - Locking tapers for electrode holders
and electrode caps (ISO 20168:2016)
Soudage par résistance - Cônes de serrage pour porte- Widerstandsschweißen - Selbsthemmende Kegel für
électrodes et pointes d'électrodes (ISO 20168:2016) Elektrodenhalter und Elektronenkappe (ISO
20168:2016)
This European Standard was approved by CEN on 6 December 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 20168:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 20168:2016 has been prepared by Technical Committee ISO/TC 44 "Welding and allied
processes” of the International Organization for Standardization (ISO) and has been taken over as
of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by July 2021, and conflicting national standards shall be
withdrawn at the latest by July 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 20168:2016 has been approved by CEN as EN ISO 20168:2021 without any modification.

INTERNATIONAL ISO
STANDARD 20168
First edition
2016-09-01
Resistance welding — Locking tapers
for electrode holders and electrode
caps
Soudage par résistance — Cônes de serrage pour porte-électrodes et
pointes d’électrodes
Reference number
ISO 20168:2016(E)
©
ISO 2016
ISO 20168:2016(E)
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
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ii © ISO 2016 – All rights reserved

ISO 20168:2016(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Dimensions and tolerances . 2
4.1 General . 2
4.2 Electrode holders . 2
4.3 Electrode caps . 2
5 Designation . 3
5.1 Electrode holders .
...