EN 4120:2004

Aerospace series - Nuts, bihexagonal, self-locking, in heat resisting nickel base alloy NI-PH1302 (Waspaloy), silver plated on thread - Classification: 1 210 MPa (at ambient temperature) / 730 °C

This standard specifies the characteristics of self-locking bihexagonal nuts in NI-P1 01 HT, silver plated on thread, for aerospace applications.
Classification: 1 210 MPa / 730 °C

Luft- und Raumfahrt - Zwölfkantmuttern, selbstsichernd, aus hochwarmfester Nickelbasislegierung NI-PH1302 (Waspaloy), Gewinde versilbert - Klasse: 1 210 MPa (bei Raumtemperatur) / 730 °C

Diese Norm legt die Eigenschaften von selbstsichernden Zwölfkantmuttern aus NI-PH1302, Gewinde versilbert, für Anwendungen in der Luft- und Raumfahrt fest.
Klasse: 1 210 MPa ) / 730 °C )

Série aérospatiale - Écrous bihexagonaux, à freinage interne, en alliage résistant à chaud à base de nickel NI-PH1302 (Waspaloy), argentés sur filetage - Classification : 1 210 MPa (à température ambiante ) / 730 °C

Aerospace series - Nuts, bihexagonal, self-locking, in heat resisting nickel base alloy NI-PH1302 (Waspaloy), silver plated on thread - Classification: 1 210 MPa (at ambient temperature) / 730 °C

General Information

• Status: Published
• Publication Date: 09-Nov-2004
• Withdrawal Date: 30-May-2005
• ICS: 49.030.30 - Nuts
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 3 - Mechanical
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 21-Jan-2025
• Completion Date: 14-May-2025
• Ref Project: SIST EN 4120:2005 - Aerospace series - Nuts, bihexagonal, self-locking, in heat resisting nickel base alloy NI-PH1302 (Waspaloy), silver plated on thread - Classification: 1 210 MPa (at ambient temperature) / 730 °C

Relations

• Replaces: EN 4120:2003 - Aerospace series - Nuts, bihexagonal, self-locking, in heat resisting nickel base alloy NI-PH-1302 (Waspaloy), silver plated on thread - Classification: 1210 MPa (at ambient temperature) / 730°C
• Effective Date: 22-Dec-2008

Overview

EN 4120:2004 is a CEN aerospace standard that defines the characteristics of self‑locking bihexagonal nuts manufactured from the heat‑resisting nickel‑base alloy NI‑PH1302 (Waspaloy) with silver‑plated threads. It specifies mechanical classification 1 210 MPa (at ambient temperature) / 730 °C, materials, dimensional limits and surface treatment requirements for use in aerospace applications where high temperature resistance and secure locking are required.

Key topics and technical requirements

• Material: Nuts shall be made from NI‑PH1302 (Waspaloy) in accordance with EN 2959 or EN 3220.
• Mechanical classification: Minimum tensile stress of 1 210 MPa at ambient temperature; maximum test temperature 730 °C (per EN 4120 footnotes).
• Geometry and tolerances: Bihexagonal (12‑point) configuration and dimensional limits are given (metric, millimetres) with tolerances applying after silver plating. Thread sizes use MJ series codes (e.g., MJ5, MJ6, MJ8, MJ10, MJ12, MJ14) aligned with ISO 5855‑2.
• Self‑locking feature: A controlled out‑of‑round form is used in the locking zone (tooling marks permissible) to achieve internal self‑locking.
• Surface treatment (silver plating): Threads and chamfers require electrolytic silver plating per EN 2786. Minimum thickness: for thread sizes ≥ MJ6, 5 µm on thread flanks; MJ5 and chamfers must show complete coverage.
• Designation and marking: Designation format (example: NUT EN4120‑050) and marking rules follow EN 2424 (style A).
• Technical specification reference: EN 3005 provides the technical specification cross‑reference for similar NI‑PH1302 nuts.

Practical applications and users

EN 4120:2004 is intended for use by organizations involved in the design, manufacture, procurement and maintenance of aerospace fasteners where high temperature performance and reliable self‑locking are required. Typical users include:

• Aerospace fastener manufacturers and forging shops
• Aircraft engine and hot‑structure component designers and engineers
• Procurement and quality assurance teams specifying certified fasteners
• Maintenance, repair and overhaul (MRO) organizations

The standard ensures consistent performance, interchangeability and traceability for Waspaloy self‑locking bihexagonal nuts used in high‑temperature aerospace environments.

Related standards

Key normative references cited in EN 4120:2004:

• ISO 4095 - Bihexagonal drives (wrenching configuration)
• ISO 5855‑2 - MJ threads limit dimensions
• EN 2424 - Marking of aerospace products
• EN 2786 - Electrolytic silver plating of fasteners
• EN 2959 / EN 3220 - NI‑PH1302 material specifications
• EN 3005 - Technical specification for similar NI‑PH1302 nuts

Keywords: EN 4120:2004, NI‑PH1302, Waspaloy, bihexagonal nuts, self‑locking nut, silver plated thread, aerospace fasteners, MJ threads.

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2005
1DGRPHãþD
SIST EN 4120:2004
Aerospace series - Nuts, bihexagonal, self-locking, in heat resisting nickel base
alloy NI-PH1302 (Waspaloy), silver plated on thread - Classification: 1 210 MPa (at
ambient temperature) / 730 °C
Aerospace series - Nuts, bihexagonal, self-locking, in heat resisting nickel base alloy NI-
PH1302 (Waspaloy), silver plated on thread - Classification: 1 210 MPa (at ambient
temperature) / 730 °C
Luft- und Raumfahrt - Zwölfkantmuttern, selbstsichernd, aus hochwarmfester
Nickelbasislegierung NI-PH1302 (Waspaloy), Gewinde versilbert - Klasse: 1 210 MPa
(bei Raumtemperatur) / 730 °C
Série aérospatiale - Écrous bihexagonaux, a freinage interne, en alliage résistant a
chaud a base de nickel NI-PH1302 (Waspaloy), argentés sur filetage - Classification : 1
210 MPa (a température ambiante ) / 730 °C
Ta slovenski standard je istoveten z: EN 4120:2004
ICS:
49.030.30 Matice Nuts
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 4120
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2004
ICS 49.030.30 Supersedes EN 4120:2003
English version
Aerospace series - Nuts, bihexagonal, self-locking, in heat
resisting nickel base alloy NI-PH1302 (Waspaloy), silver plated
on thread - Classification: 1 210 MPa (at ambient temperature) /
730° C
Série aérospatiale - Écrous bihexagonaux, à freinage Luft- und Raumfahrt - Zwölfkantmuttern, selbstsichernd,
interne, en alliage résistant à chaud à base de nickel NI- aus hochwarmfester Nickelbasislegierung NI-PH1302
PH1302 (Waspaloy), argentés sur filetage - Classification : (Waspaloy), Gewinde versilbert - Klasse: 1 210 MPa (bei
1 210 MPa (à température ambiante ) / 730° C Raumtemperatur) / 730° C
This European Standard was approved by CEN on 11 September 2003.

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© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4120:2004: E
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Contents                                                                         Page

Foreword.3
1 Scope .4
2 Normative references .4
3 Required characteristics.4
4 Designation .6
5 Marking .6
6 Technical specification .6
Foreword
This document (EN 4120:2004) has been prepared by the European Association of Aerospace
Manufacturers - Standardization (AECMA-STAN).
After enquiries and votes carried out in acco
...