FprEN 2942

• Abstract:

  This document specifies the characteristics of inserts self-locking, helical coil tanged insertion drive, MJ screw threads in NI-PH2801, silver plated, for aerospace applications.; Maximum test temperature: 550 °C.

• Status: Not Published
• Publication Date: 29-Nov-2026
• ICS: 49.030.30 - Nuts
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 3/S 2 - Fasteners
• Current Stage: 6055 - CEN Ratification completed (DOR) - Publishing
• Start Date: 28-Sep-2026
• Completion Date: 28-Sep-2026
• Ref Project: kSIST FprEN 2942:2026 - Aerospace series - Insert, MJ screw thread, helical coil, self-locking tanged insertion drive, in heat resisting nickel base alloy NI-PH2801 (Inconel X750), silver plated

• Revises: EN 2942:1998 - Aerospace series - Inserts, screw thread, helical coil, self-locking, in heat resisting nickel base alloy NI-PH2801 (Inconel X750), silver plated
• Effective Date: 19-Jan-2023

FprEN 2942 is a draft European standard from CEN for aerospace inserts with MJ screw thread, made as helical coil, self-locking, and tanged insertion drive. It specifies the characteristics of these silver-plated inserts in heat-resisting nickel base alloy NI-PH2801 (Inconel X750) for aerospace applications, with a maximum test temperature of 550 °C.

What does FprEN 2942 specify?

FprEN 2942 specifies the characteristics of self-locking helical coil inserts with MJ screw threads in NI-PH2801, silver plated, for aerospace use. The document is organized into clauses 1 to 8, covering scope, normative references, terms and definitions, required characteristics, designation, marking, technical specification, and quality management systems, followed by a bibliography.

Clause 4 is the core of the document. It gives the configuration, dimensions, tolerances, masses, material, and surface treatment that define the product for design and procurement.

What are the key requirements of FprEN 2942?

FprEN 2942 ties the product to a set of geometric, material, finish, marking, and quality requirements. In practice, this means the insert is not defined only by thread form, but also by the finished dimensions, base material, plating, and how it is identified and controlled in production.

Geometry and dimensions

• Clause 4.1 points to Figure 1, Table 1, and Table 2 for the product shape and sizes.
• Dimensions and tolerances are given in millimetres and apply after silver plating.
• Surface roughness values Ra apply before silver plating.
• Details of form that are not stated are left to the manufacturer’s discretion.
• The tables cover sizes from MJ4 × 0,7 up to MJ10 × 1,25, with associated dimensions and masses.

For users, this is the main data needed to design the mating hole, check fit, and inspect delivered parts. Table 2 also shows the installed dimensions and mass, so buyers and inspectors can verify the final assembly condition, not just the loose part.

Self-locking and installation-related features

• Figure 1 identifies the tang, the number of coils, the installed thread length, and the fitting relationship with the installation hole.
• The self-locking feature is linked to the out-of-round zone shown in the figure.
• Some dimensions, such as X and Y, apply after installation.

In practice, this tells the designer and installer which features matter for the locking function and which measurements are relevant only after the insert has been fitted.

Material and surface treatment

• Clause 4.2 requires the material to conform to EN 3018.
• Clause 4.3 requires surface treatment to conform to EN 2786.
• The silver plating thickness is 2 μm to 5 μm.

This matters because the alloy and the plated finish affect temperature capability, corrosion behaviour, and thread performance. The plating thickness is part of acceptance, so it has to be controlled during manufacture and inspection.

Designation, marking, and product identification

• Clause 5 defines the designation format and notes that code I9005 may be inserted when needed.
• Clause 6 requires marking according to EN 2424.
• Marking style G is required, and style F is also permitted where shown in Figure 1.

For users, this supports traceability and ordering. It also tells the manufacturer how the part should be identified on the product itself.

Technical specification and quality control

• Clause 7 sends the technical specification to EN 2943.
• Clause 8 requires the manufacturer to be an approved production organization for aerospace products.
• Clause 8 also calls for a quality management system such as EN 9100, or an equivalent aerospace accepted and established system.
• Qualification should use a procedure such as EN 9133, or an equivalent procedure, and be documented according to the specified tests unless otherwise agreed.

In practice, this means the document is not only about product dimensions. It also sets expectations for how the supplier controls production and demonstrates conformity.

What terms does FprEN 2942 define?

FprEN 2942 does not list formal terms and definitions, but it uses several key terms that matter for reading the document.

• MJ screw thread - the aerospace thread form used for the insert, with limit dimensions taken from ISO 5855-2.
• NI-PH2801 - the heat-resisting nickel base alloy specified for the insert material.
• Self-locking - the insert includes a locking feature intended to resist loosening in service.
• Tanged insertion drive - the tang is the drive feature used during installation of the helical coil insert.
• EN 2424 - the marking standard referenced for identifying aerospace products.
• EN 9100 - an example of the quality management system expected from the manufacturer.

Who uses FprEN 2942?

FprEN 2942 is used by aerospace designers, fastener and insert manufacturers, installation and assembly teams, quality managers, and buyers. Designers use it to specify the insert and the mating installation hole, manufacturers use it to make and inspect the parts, and quality teams use it for acceptance, marking, and qualification checks.

It is relevant wherever aerospace threaded inserts must perform in a silver-plated, high-temperature nickel alloy form. That makes it useful in procurement, incoming inspection, and supplier approval as well as product design.

What changed in FprEN 2942 from the previous edition?

FprEN 2942 will supersede EN 2942:1998.

Which standards are used with FprEN 2942?

Standard	What it contributes
EN 2424	Marking of aerospace products
EN 2786	Electrolytic silver plating of fasteners
EN 2943	Technical specification for inserts, MJ and M screw threads, helical coil
EN 3018	Material requirement for NI-PH2801 wire used to manufacture thread inserts
EN 3044	Design standard for installation holes for self-locking helical coil inserts
ISO 5855-2	Limit dimensions for MJ bolts and nuts
EN 2945	Assembly procedure for self-locking helical coil inserts, cited in the introduction
EN 9100	Example of an aerospace quality management system
EN 9133	Example of an aerospace qualification procedure

What does the FprEN 2942 document contain?

FprEN 2942 contains one layout drawing and two main data tables in Clause 4. Figure 1 shows the insert layout for design use, while Table 1 gives the dimensional data and Table 2 gives the dimensions and masses for the covered thread sizes. The document also contains the designation rule, the marking requirement, the link to the technical specification in EN 2943, and the quality management expectations for production organizations.

For a reader, the practical value is in the tables and figure: they support design of the mating hole, procurement description, installation planning, and inspection after plating and after assembly.

SLOVENSKI STANDARD
oSIST prEN 2942:2022
01-april-2022
Aeronavtika - Vložek s spiralnim navojem MJ, samozapiralni, za ročno vstavljanje,
iz toplotno odporne zlitine na nikljevi osnovi NI-PH2801 (Inconel X750), posrebreni
Aerospace series - Insert, MJ screw thread, helical coil, self-locking tanged insertion
drive, in heat resisting nickel base alloy NI-PH2801 (Inconel X750), silver plated
Luft- und Raumfahrt - Draht-Gewindeeinsätze, selbstsichernd, aus hochwarmfester
Nickelbasislegierung NI-PH2801 (Inconel X750 - EN 3018), versilbert
Série aérospatiale - Filet rapportés, à freinage interne, en alliage résistant à chaud à
base de nickel NI-PH2801 (Inconel X750), argentés
Ta slovenski standard je istoveten z: prEN 2942:2022
ICS:
49.030.20 Sorniki, vijaki, stebelni vijaki Bolts, screws, studs
oSIST prEN 2942:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 2942:2022
oSIST prEN 2942:2022
DRAFT
EUROPEAN STANDARD
prEN 2942
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2022
ICS Will supersede EN 2942:1998
English Version
Aerospace series - Insert, MJ screw thread, helical coil, self-
locking tanged insertion drive, in heat resisting nickel base
alloy NI-PH2801 (Inconel X750), silver plated
Série aérospatiale - Filet rapportés, à freinage interne, Luft- und Raumfahrt - Draht-Gewindeeinsätze,
en alliage résistant à chaud à base de nickel NI-PH2801 selbstsichernd, aus hochwarmfester
(Inconel X750), argentés Nickelbasislegierung NI-PH2801 (Inconel X750 - EN
3018), versilbert
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, Turkey 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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 2942:2022:2022 E
worldwide for CEN national Members.

oSIST prEN 2942:2022
prEN 2942:2022 (E)
Contents Page
European Foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Required characteristics . 5
4.1 Configuration — Dimensions — Tolerances — Masses . 5
4.2 Material . 8
4.3 Surface treatment . 8
5 Designation . 8
6 Marking . 8
7 Technical specification . 8
8 Quality management systems . 8
Bibliography . 9

oSIST prEN 2942:2022
prEN 2942:2022 (E)
European Foreword
This document (prEN 2942:2022) has been prepared by the Aerospace and Defence Industries
Association of Europe — Standardization (ASD-STAN).
This document is currently submitted to the CEN Enquiry
...