Aerospace series - Inserts, MJ and M screw threads, helical coil - Technical specification

This European standard specifies the characteristics, qualification and acceptance requirements for helical coil screw thread inserts.
It is applicable whenever referenced.

Luft- und Raumfahrt - Draht-Gewindeeinsätze, MJ und M Gewinde -Technische Lieferbedingungen

Diese Europäische Norm legt die Eigenschaften sowie die Qualifikations- und Annahmebedingungen für Draht-Gewindeeinsätze fest.
Sie ist anzuwenden, wenn auf sie Bezug genommen wird.

Série aérospatiale - Filets rapportés, filetages MJ et M - Spécification technique

La présente norme européenne spécifie les caractéristiques, et les exigences de qualification et de réception des filets rapportés hélicoïdaux.
Elle est applicable chaque fois qu'elle est citée en référence.

Aeronavtika - Vložki s spiralnim navojem MJ in M - Tehnična specifikacija

Ta evropski standard določa karakteristike ter zahteve glede kvalifikacije in sprejemljivosti za vložke s spiralnim navojem za vijačne tuljave. Uporablja se, kadar je naveden.

General Information

Status
Published
Publication Date
19-Nov-2019
Technical Committee
Drafting Committee
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
20-Nov-2019
Completion Date
20-Nov-2019

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SLOVENSKI STANDARD
SIST EN 2943:2020
01-januar-2020
Nadomešča:
SIST EN 2943:2001
Aeronavtika - Vložki s spiralnim navojem MJ in M - Tehnična specifikacija

Aerospace series - Inserts, MJ and M screw threads, helical coil - Technical specification

Luft- und Raumfahrt - Draht-Gewindeeinsätze, MJ und M Gewinde -Technische
Lieferbedingungen
Série aérospatiale - Filets rapportés MJ et M filetage - Spécification technique
Ta slovenski standard je istoveten z: EN 2943:2019
ICS:
49.030.20 Sorniki, vijaki, stebelni vijaki Bolts, screws, studs
SIST EN 2943:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 2943:2020
---------------------- Page: 2 ----------------------
SIST EN 2943:2020
EN 2943
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2019
EUROPÄISCHE NORM
ICS 49.030.30 Supersedes EN 2943:1998
English Version
Aerospace series - Inserts, MJ and M screw threads, helical
coil - Technical specification

Série aérospatiale - Filets rapportés, filetages MJ et M - Luft- und Raumfahrt - Draht-Gewindeeinsätze, MJ- und

Spécification technique M-Gewinde - Technische Lieferbedingungen
This European Standard was approved by CEN on 7 July 2019.

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

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 2943:2019 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)
Contents
Page

European foreword ....................................................................................................................................................... 3

1 Scope .................................................................................................................................................................... 4

2 Normative references .................................................................................................................................... 4

3 Terms and definitions ................................................................................................................................... 4

4 Quality assurance ............................................................................................................................................ 7

4.1 Approval of manufacturers ......................................................................................................................... 7

4.2 Qualification ...................................................................................................................................................... 7

4.3 Acceptance ......................................................................................................................................................... 7

4.3.1 Purpose ............................................................................................................................................................... 7

4.3.2 Conditions .......................................................................................................................................................... 7

4.3.3 Responsibility ................................................................................................................................................... 7

4.3.4 Inspection and test report ........................................................................................................................... 7

5 Requirements ................................................................................................................................................... 7

Annex A (normative) Definition of maximum and minimum test bolts for the permanent set

test ..................................................................................................................................................................... 16

Annex B (normative) Assembly for permanent set test .............................................................................. 18

Annex C (normative) Definition of test bolt for reusability test............................................................... 19

Annex D (normative) Definition of spacer for reusability tests ............................................................... 20

Bibliography ................................................................................................................................................................. 22

---------------------- Page: 4 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)
European foreword

This document (EN 2943:2019) has been prepared by the Aerospace and Defence Industries

Association of Europe - Standardization (ASD-STAN).

After enquiries and votes carried out in accordance with the rules of this Association, this Standard has

received the approval of the National Associations and the Official Services of the member countries of

ASD, prior to its presentation to CEN.

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 May 2020, and conflicting national standards shall be

withdrawn at the latest by May 2020.

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.

This document supersedes EN 2943:1998.

According to the CEN-CENELEC Internal Regulations, the national standards organisations 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.
---------------------- Page: 5 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)
1 Scope

This European standard specifies the characteristics, qualification and acceptance requirements for

helical coil screw thread inserts.
It is applicable whenever referenced.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

EN 2398, Aerospace series — Heat resisting steel FE-PA2601 (X6NiCrTiMoV26-15) — R ≥ 900 MPa —

Bars for machined bolts — D ≤ 25 mm

EN 2945, Aerospace series — Inserts, screw thread, helical coil, self-locking — Assembly procedure

EN 3044, Aerospace series — Installation holes for inserts, screw thread, helical coil, self-locking — Design

standard

EN 3219, Aerospace series — Heat resisting nickel base alloy (Ni-P100HT) — Cold worked and softened —

Bar and wire for continuous forging or extrusion for fasteners — 3 mm ≤ D ≤ 30 mm

EN 9138, Aerospace Series — Quality Management Systems — Statistical Product — Acceptance

Requirements

ISO 965-2, ISO general purpose metric screw threads — Tolerances — Part 2: Limits of sizes for general

purpose external and internal screw threads — Medium quality
ISO 3353 (all parts), Aerospace — Lead and runout threads

ISO 4288, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Rules and

procedures for the assessment of surface texture
ISO 5855-2, Aerospace — MJ threads — Part 2: Limit dimensions for bolts and nuts
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

 ISO Online browsing platform: available at http://www.iso.org/obp
 IEC Electropedia: available at http://www.electropedia.org/

1 Published as ASD-STAN Prestandard at the date of publication of this standard by AeroSpace and Defence

Industries Association of Europe – Standardization (ASD-STAN) (www.asd-stan.org).

---------------------- Page: 6 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)
3.1
batch

quantity of finished thread inserts, of the same type and same diameter, produced from a material

obtained from the same melt, manufactured in the course of the same production cycle, following the

same manufacturing route and having undergone all the relevant heat treatments and surface treat-

ments
3.2 surface discontinuities
3.2.1
crack

rupture in the material which may extend in any direction and which may be intercrystalline or

transcrystalline in character
3.2.2
seam
open surface defect
3.2.3
lap

surface defect caused by folding over metal fins or sharp corners and then compressing them into the

surface
3.2.4
inclusions
non-metallic particles originating from the material manufacturing process
Note 1 to entry: These particles may be isolated or arranged in strings.
3.3
test temperature
ambient temperature, unless otherwise specified
3.4
simple random sampling

sampling where a sample of n sampling units is taken from a population in such a way that all the

possible combinations of n sampling units have the same probability of being taken

3.5 sampling test and examinations

Note 1 to entry: Shall be in accordance with the requirements of EN 9138. Acceptance quality shall be based on

zero imperfections.
3.5.1
non-destructive tests-visual and dimensional

random sample shall be selected from each production lot, the size for the sample to be as specified in

Table 2. All dimensional characteristics are considered imperfect when out of tolerance

3.5.2
destructive tests- screw locking torque

random sample shall be selected from each production sample lot as per Table 2. Normal size

inspection shall be in effect until conditions for adjusting from normal to reduced size are satisfied.

Normal size inspection shall resume when the conditions for switching from reduced to normal size

occur
---------------------- Page: 7 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)
3.5.2.1
normal to reduced sample size switching

switching from normal to reduced sample shall be instituted providing the following conditions are

satisfied:

a) the preceding 10 batches have been on normal inspection and all have been accepted;

b) production of a sample item or items using similar processes has been continuous under normal

size sampling without break longer than 90 days;
c) reduced inspection is considered desirable
3.5.2.2
reduced to normal sample size switching

when reduced sample size inspection is in effect, normal sample size inspection shall be instituted if any

of following conditions occur on original inspection:
a) a batch is rejected;

b) production of a sample item using similar processes ceases or is delayed for a period greater than

90 days;
c) other conditions warrant that normal size inspection is resumed
3.6
finished thread insert

thread insert ready for use, inclusive of any possible treatments and/or surface coatings, as specified in

the product standards or definition document
3.7
definition document
document specifying all the requirements for finished thread inserts
3.8
self-locking torque

torque to be applied to the associated bolt to maintain its movement of rotation in relation to the thread

insert assembly which is under no axial load and the thread insert locking zone being completely

engaged with the bolt (minimum protrusion of two pitches, including the end chamfer)

3.9
seating torque

tightening torque to be applied to the thread insert and bolt assembly to introduce or to increase the

axial load in the assembly
3.10
unseating torque

untightening torque to be applied to the thread insert and bolt assembly to reduce or remove the axial

load in the assembly
3.11
breakaway torque

torque required to start unscrewing the associated bolt with respect to the installed thread insert, with

the insert locking zone still fully engaged on the bolt, but after the axial load in the assembly has been

removed by unscrewing half a turn followed by a halt in rotational movement
---------------------- Page: 8 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)
4 Quality assurance
4.1 Approval of manufacturers

The manufacturer’s operations shall be an approved production organisation for aerospace products

and shall demonstrate that it has implemented and is able to maintain a quality management system

(e. g. according to EN 9100 or an equivalent aerospace accepted and established quality management

system).
4.2 Qualification

The qualification procedure for aerospace standard products (e. g. according to EN 9133 or an

equivalent aerospace accepted and established qualification procedure) shall be used and documented

according to the specified tests if not otherwise agreed between customer and supplier.

Qualification inspections and tests (requirements, methods, numbers of thread inserts) are specified in

Table 1. They shall be carried out on
 each type and diameter of thread insert and
 26 thread inserts selected from a single batch by simple random sampling.
The test programme may possibly be reduced, or the qualification
...

SLOVENSKI STANDARD
SIST EN 2943:2020
01-januar-2020
Nadomešča:
SIST EN 2943:2001
Aeronavtika - Vložki s spiralnim navojem MJ in M - Tehnična specifikacija

Aerospace series - Inserts, MJ and M screw threads, helical coil - Technical specification

Luft- und Raumfahrt - Draht-Gewindeeinsätze, MJ und M Gewinde -Technische
Lieferbedingungen
Série aérospatiale - Filets rapportés MJ et M filetage - Spécification technique
Ta slovenski standard je istoveten z: EN 2943:2019
ICS:
49.030.20 Sorniki, vijaki, stebelni vijaki Bolts, screws, studs
SIST EN 2943:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 2943:2020
---------------------- Page: 2 ----------------------
SIST EN 2943:2020
EN 2943
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2019
EUROPÄISCHE NORM
ICS 49.030.30 Supersedes EN 2943:1998
English Version
Aerospace series - Inserts, MJ and M screw threads, helical
coil - Technical specification

Série aérospatiale - Filets rapportés, filetages MJ et M - Luft- und Raumfahrt - Draht-Gewindeeinsätze, MJ- und

Spécification technique M-Gewinde - Technische Lieferbedingungen
This European Standard was approved by CEN on 7 July 2019.

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

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 2943:2019 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

1 Scope .................................................................................................................................................................... 3

2 Normative references .................................................................................................................................... 3

3 Terms and definitions ................................................................................................................................... 4

4 Quality assurance ............................................................................................................................................ 6

4.1 Approval of manufacturers ......................................................................................................................... 6

4.2 Qualification ...................................................................................................................................................... 6

4.3 Acceptance ......................................................................................................................................................... 6

4.3.1 Purpose ............................................................................................................................................................... 6

4.3.2 Conditions .......................................................................................................................................................... 7

4.3.3 Responsibility ................................................................................................................................................... 7

4.3.4 Inspection and test report ........................................................................................................................... 7

5 Requirements ................................................................................................................................................... 7

Annex A (normative) Definition of maximum and minimum test bolts for the permanent set

test ..................................................................................................................................................................... 14

Annex B (normative) Assembly for permanent set test .............................................................................. 16

Annex C (normative) Definition of test bolt for reusability test............................................................... 17

Annex D (normative) Definition of spacer for reusability tests ............................................................... 18

Bibliography ................................................................................................................................................................. 20

---------------------- Page: 4 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)
European foreword

This document (EN 2943:2019) has been prepared by the Aerospace and Defence Industries

Association of Europe - Standardization (ASD-STAN).

After enquiries and votes carried out in accordance with the rules of this Association, this Standard has

received the approval of the National Associations and the Official Services of the member countries of

ASD, prior to its presentation to CEN.

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 May 2020, and conflicting national standards shall be

withdrawn at the latest by May 2020.

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.

This document supersedes EN 2943:1998.

According to the CEN-CENELEC Internal Regulations, the national standards organisations 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.
1 Scope

This European standard specifies the characteristics, qualification and acceptance requirements for

helical coil screw thread inserts.
It is applicable whenever referenced.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

EN 2398, Aerospace series — Heat resisting steel FE-PA2601 (X6NiCrTiMoV26-15) — R ≥ 900 MPa —

Bars for machined bolts — D ≤ 25 mm

EN 2945, Aerospace series — Inserts, screw thread, helical coil, self-locking — Assembly procedure

EN 3044, Aerospace series — Installation holes for inserts, screw thread, helical coil, self-locking — Design

standard

EN 3219, Aerospace series — Heat resisting nickel base alloy (Ni-P100HT) — Cold worked and

softened — Bar and wire for continuous forging or extrusion for fasteners — 3 mm ≤ D ≤ 30 mm

Published as ASD-STAN Prestandard at the date of publication of this standard by AeroSpace and Defence

Industries Association of Europe – Standardization (ASD-STAN) (www.asd-stan.org).

---------------------- Page: 5 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)

EN 9138, Aerospace Series — Quality Management Systems — Statistical Product — Acceptance

Error! Bookmark not defined.
Requirements

ISO 965-2, ISO general purpose metric screw threads — Tolerances — Part 2: Limits of sizes for general

purpose external and internal screw threads — Medium quality
ISO 3353 (all parts), Aerospace — Lead and runout threads

ISO 4288, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Rules and

procedures for the assessment of surface texture
ISO 5855-2, Aerospace — MJ threads — Part 2: Limit dimensions for bolts and nuts
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at http://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
batch

quantity of finished thread inserts, of the same type and same diameter, produced from a material

obtained from the same melt, manufactured in the course of the same production cycle, following the

same manufacturing route and having undergone all the relevant heat treatments and surface

treatments
3.2 surface discontinuities
3.2.1
crack

rupture in the material which may extend in any direction and which may be intercrystalline or

transcrystalline in character
3.2.2
seam
open surface defect
3.2.3
lap

surface defect caused by folding over metal fins or sharp corners and then compressing them into the

surface
3.2.4
inclusions
non-metallic particles originating from the material manufacturing process
Note 1 to entry: These particles may be isolated or arranged in strings.
3.3
test temperature
ambient temperature, unless otherwise specified
---------------------- Page: 6 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)
3.4
simple random sampling

sampling where a sample of n sampling units is taken from a population in such a way that all the

possible combinations of n sampling units have the same probability of being taken

3.5 sampling test and examinations
3.5.1
non-destructive tests-visual and dimensional

random sample shall be selected from each production lot, the size for the sample to be as specified in

Table 2. All dimensional characteristics are considered imperfect when out of tolerance

3.5.2
destructive tests- screw locking torque

random sample shall be selected from each production sample lot as per Table 2. Normal size

inspection shall be in effect until conditions for adjusting from normal to reduced size are satisfied.

Normal size inspection shall resume when the conditions for switching from reduced to normal size

occur
3.5.2.1
normal to reduced sample size switching

switching from normal to reduced sample shall be instituted providing the following conditions are

satisfied:

a) the preceding 10 batches have been on normal inspection and all have been accepted;

b) production of a sample item or items using similar processes has been continuous under normal

size sampling without break longer than 90 days;
c) reduced inspection is considered desirable
3.5.2.2
reduced to normal sample size switching

when reduced sample size inspection is in effect, normal sample size inspection shall be instituted if any

of following conditions occur on original inspection:
a) a batch is rejected;

b) production of a sample item using similar processes ceases or is delayed for a period greater than

90 days;
c) other conditions warrant that normal size inspection is resumed
3.6
finished thread insert

thread insert ready for use, inclusive of any possible treatments and/or surface coatings, as specified in

the product standards or definition document
3.7
definition document
document specifying all the requirements for finished thread inserts
---------------------- Page: 7 ----------------------
SIST EN 2943:2020
EN 2943:2019 (E)
3.8
self-locking torque

torque to be applied to the associated bolt to maintain its movement of rotation in relation to the thread

insert assembly which is under no axial load and the thread insert locking zone being completely

engaged with the bolt (minimum protrusion of two pitches, including the end chamfer)

3.9
seating torque

tightening torque to be applied to the thread insert and bolt assembly to introduce or to increase the

axial load in the assembly
3.10
unseating torque

untightening torque to be applied to the thread insert and bolt assembly to reduce or remove the axial

load in the assembly
3.11
breakaway torque

torque required to start unscrewing the associated bolt with respect to the installed thread insert, with

the insert locking zone still fully engaged on the bolt, but after the axial load in the assembly has been

removed by unscrewing half a turn followed by a halt in rotational movement
4 Quality assurance
4.1 Approval of manufacturers

The manufacturer’s operations shall be an approved production organisation for aerospace products

and shall demonstrate that it has implemented and is able to maintain a quality management system

(e. g. according to EN 9100 or an equivalent aerospace accepted and established quality management

system).
4.2 Qualification

The qualification procedure for aerospace standard products (e. g. according to EN 9133 or an

equivalent aerospace accepted and established qualification procedure) shall be used and documented

according to the specified tests if not otherwise agreed between customer and supplier.

Qualification inspections and tests (requirements, methods, numbers of thread inserts) are specified in

Table 1. They shall be carried out on
— each type and diameter of thread insert and
— 26 thread inserts selected from a single batch by simple random sampling.

The test programme may possibly be reduced, or the qualification be granted without inspection or

testing: any such decision shall be based on the results obtained on similar types and diameters of

thread inserts provided that the design and manufacturing conditions are identical.

4.3 Acceptance
4.3.1 Purpose
The purpose of acceptance ins
...

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