oSIST prEN 2948:2026
(Main)Aerospace series - Washers, tab, in heat resisting steel, passivated
- Abstract
This document specifies the characteristics of tab washers, in heat resisting steel, passivated, for maximum operating temperature 650 °C, for aerospace applications.
Their use under hexagon head bolts is conditional upon the user accepting the possibility of some interference.
- Status
- Not Published
- Public Enquiry End Date
- 24-Feb-2026
- Technical Committee
- I13 - Imaginarni 13
- Current Stage
- 4020 - Public enquire (PE) (Adopted Project)
- Start Date
- 22-Dec-2025
- Due Date
- 11-May-2026
- Completion Date
- 25-Feb-2026
oSIST prEN 2948:2026 is a CEN draft European standard for tab washers in heat resisting steel, passivated, for aerospace applications. It specifies the washers for a maximum operating temperature of 650 °C and sets out the characteristics, inspection methods and quality assurance expected for manufactured parts. For engineers, buyers and quality managers, it is the reference for specifying, identifying and checking these locking washers.
What does oSIST prEN 2948:2026 specify?
oSIST prEN 2948:2026 specifies the characteristics of tab washers in heat resisting steel, passivated, for aerospace use. It also notes a practical limitation: use under hexagon head bolts depends on the user accepting the possibility of some interference.
The document is organized into clauses on scope, normative references, terms and definitions, required characteristics, designation, marking, inspections and tests, and quality assurance, plus one informative annex.
| Annex | What it covers |
|---|---|
| Annex A | Bending test and installation example |
What are the key requirements of oSIST prEN 2948:2026?
Dimensions, material and surface treatment
oSIST prEN 2948:2026 ties the washer shape, dimensions and masses to Figure 1 and Table 1. The dimensions are given in millimetres, and the tolerances apply after surface treatment, so finished parts are what matter for conformity.
The material shall comply with EN 2175, and the surface treatment shall comply with EN 2516. In practice, this means the washer supplier has to control both the base material and the passivation process, not just the final geometry.
Identification and marking
oSIST prEN 2948:2026 requires a designation format of the form TAB WASHER EN 2948-080, where the diameter code identifies the size. This gives buyers and production teams a common ordering and traceability reference.
Marking shall follow EN 2424, style G. That matters because the part marking has to fit aerospace marking practice and stay aligned with the product identification system used across the supply chain.
Inspection and bend test
oSIST prEN 2948:2026 requires visual examination of sample parts for burrs, scratches and cracks, with the sample size set by the delivered quantity. For the reader, this means incoming inspection or final inspection must be planned against the shipment size, not by a single fixed sample.
The bend test applies to 0.1% of the washers to be inspected, with at least three parts. The parts are assembled under normal operating conditions, then the locking tabs are folded and straightened twice; they must remain free from cracks. Annex A gives the detailed bending test and installation example.
Quality assurance
oSIST prEN 2948:2026 states that the manufacturer shall be an approved production organization for aerospace products and shall maintain a quality management system such as EN 9100 or an equivalent accepted aerospace system. It also calls for a qualification procedure such as EN 9133 or an equivalent agreed procedure, documented against the specified tests.
In practice, the standard expects controlled production, documented verification and a defined route for product qualification, not just dimensional checks on finished washers.
Who uses oSIST prEN 2948:2026?
oSIST prEN 2948:2026 is used by aerospace manufacturers, suppliers of fastening components, quality managers, inspectors and procurement teams. It is relevant when specifying, making, marking, qualifying or receiving tab washers for aerospace assemblies.
It is also useful to engineers who need a standardized locking washer with known material, surface treatment and test requirements for high-temperature service.
What changed in oSIST prEN 2948:2026 from the previous edition?
oSIST prEN 2948:2026 will supersede EN 2948:1996. The foreword lists these technical changes compared with the previous edition:
- Clause 3, “Terms and definitions”, was added.
- Clause 8, “Quality assurance”, was updated.
- Annex A, “Bending test and installation example”, was added.
Which standards are used with oSIST prEN 2948:2026?
| Standard | Contribution |
|---|---|
| EN 2175 | Specifies the heat resisting alloy material used for the washers |
| EN 2424 | Defines the marking style for aerospace products |
| EN 2516 | Defines passivation of corrosion resisting steels and decontamination of nickel or cobalt base alloys |
| EN 9100 | Example of an acceptable aerospace quality management system in Clause 8 |
| EN 9133 | Example of an acceptable qualification procedure for aerospace standard products |
What does the oSIST prEN 2948:2026 document contain?
oSIST prEN 2948:2026 contains a defined washer configuration in Figure 1, a dimension-and-mass table for the size codes, and an example designation for ordering and identification. It also includes a visual examination table that sets the minimum inspection sample by delivered quantity.
For testing and use, the document gives the bend test requirements in Clause 7 and expands them in Annex A with a bending test illustration and installation examples. Annex A also includes a dimension table for the bending/installation examples and figures showing how the washer is folded and anchored in service.
Relations
- Effective Date
- 23-Jul-2025
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Frequently Asked Questions
oSIST prEN 2948:2026 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Aerospace series - Washers, tab, in heat resisting steel, passivated". This standard covers: This document specifies the characteristics of tab washers, in heat resisting steel, passivated, for maximum operating temperature 650 °C, for aerospace applications. Their use under hexagon head bolts is conditional upon the user accepting the possibility of some interference.
This document specifies the characteristics of tab washers, in heat resisting steel, passivated, for maximum operating temperature 650 °C, for aerospace applications. Their use under hexagon head bolts is conditional upon the user accepting the possibility of some interference.
oSIST prEN 2948:2026 is classified under the following ICS (International Classification for Standards) categories: 49.030.50 - Washers and other locking elements. The ICS classification helps identify the subject area and facilitates finding related standards.
oSIST prEN 2948:2026 has the following relationships with other standards: It is inter standard links to SIST EN 2948:2001. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
oSIST prEN 2948:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-februar-2026
Aeronavtika - Podložke, z zatičnim jezičkom, iz toplotno odpornega jekla,
pasivirane
Aerospace series - Washers, tab, in heat resisting steel, passivated
Luft- und Raumfahrt - Sicherungsblech mit Lappen aus hochwarmfestem Stahl,
passiviert
Ta slovenski standard je istoveten z: prEN 2948
ICS:
49.030.50 Podložke in drugi blokirni Washers and other locking
elementi elements
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
prEN 2948
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2025
ICS 49.030.50 Will supersede EN 2948:1996
English Version
Aerospace series - Washers, tab, in heat resisting steel,
passivated
Luft- und Raumfahrt - Sicherungsblech mit Lappen aus
hochwarmfestem Stahl, passiviert
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-
STAN.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 2948:2025 E
worldwide for CEN national Members.
prEN 2948:2025 (E)
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Required characteristics . 4
4.1 Configuration – Dimensions – Masses . 4
4.2 Material . 4
4.3 Surface treatment . 4
5 Designation . 6
6 Marking . 6
7 Inspections and tests . 6
7.1 Appearance . 6
7.2 Bend test . 6
8 Quality assurance . 6
Annex A (informative) Bending test and installation example . 7
Bibliography . 10
prEN 2948:2025 (E)
European foreword
This document (prEN 2948:2025) has been prepared by ASD-STAN.
After enquiries and votes carried out in accordance with the rules of this Association, this document has
received the approval of the National Associations and the Official Services of the member countries of
ASD-STAN, prior to its presentation to CEN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 2948:1996.
This document includes the following significant technical changes with respect to EN 2948:1996:
— Clause 3 “Terms and definitions” added;
— Clause 8 “Quality assurance” updated;
— Annex A “Bending test and instal
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