ISO 9154:2016

Aerospace - Bolts, with MJ threads, made of heat-resistant nickel-based alloy, strength class 1 550 MPa - Procurement specification

ISO 9154.2016 specifies the characteristics and quality assurance requirements for MJ threads bolts made of heat-resisting nickel-base alloy, of strength class 1 550 MPa, for aerospace construction. It is applicable whenever it is referenced in a definition document.

Aéronautique et espace — Vis à filetage MJ, en alliage résistant à chaud à base de nickel, classe de résistance 1 550 MPa — Spécification d'approvisionnement

General Information

• Status: Published
• Publication Date: 17-Feb-2016
• ICS: 49.030.20 - Bolts, screws, studs
• Technical Committee: ISO/TC 20/SC 4 - Aerospace fastener systems
• Drafting Committee: ISO/TC 20/SC 4 - Aerospace fastener systems
• Current Stage: 9093 - International Standard confirmed
• Start Date: 31-Oct-2022
• Completion Date: 13-Dec-2025

Relations

• Revises: ISO 9154:1999 - Aerospace - Bolts, with MJ threads, made of heat-resistant nickel-based alloy, strength class 1 550 MPa - Procurement specification
• Effective Date: 04-Nov-2015

Overview

ISO 9154:2016 - titled Aerospace - Bolts, with MJ threads, made of heat-resistant nickel‑based alloy, strength class 1 550 MPa - Procurement specification - is an international procurement and quality assurance standard for high‑strength, heat‑resistant aerospace bolts. It specifies the required characteristics, inspection regimes and documentation for MJ‑thread bolts manufactured from nickel‑base alloys rated 1 550 MPa, and it applies whenever this standard is cited in a definition document.

Key topics and requirements

• Scope and applicability
  • Covers MJ‑thread bolts for aerospace construction made from heat‑resisting nickel‑base alloys of strength class 1 550 MPa.
  • Applies when referenced by a definition document (e.g., drawing or internal specification).
• Quality assurance and approval
  • Manufacturer approval and qualification required by Certification Authorities (EASA/FAA or equivalent).
  • Manufacturers expected to maintain quality systems such as AS9100 / EN9100 and retain records for a minimum of 10 years.
• Qualification and acceptance inspections
  • Defined sampling plans for qualification and acceptance (simple random sampling, inspection lot and batch definitions).
  • Procedures for destructive and non‑destructive testing; re‑inspection rules for rejected lots.
• Manufacturing controls
  • Requirements for forging, heat treatment (limits on number of heat treatments), thread forming (roll‑formed threads), fillet rolling after heat treatment, surface roughness and surface coatings.
  • Passivation of uncoated finished bolts is required (Annex A) with salt‑spray performance criteria.
• Mechanical testing
  • Tensile, tension fatigue and stress‑rupture load considerations are referenced; tensile testing standards and specimen rules are specified.
• Statistical Process Control (SPC)
  • Option to substitute final sampling with validated SPC methods (ISO/TR 13425 and ISO 7870 series guidance), subject to qualification/approval.

Practical applications and users

Who uses ISO 9154:2016:

• Aerospace OEMs and prime contractors specifying high‑temperature fasteners.
• Fastener manufacturers and heat‑treat shops producing MJ‑thread nickel‑base bolts.
• Procurement engineers creating definition documents and purchase orders.
• Quality managers, inspectors and certification authorities responsible for supplier approval and lot acceptance. Why it matters:
• Ensures traceability, mechanical reliability and corrosion resistance of critical high‑temperature fasteners.
• Reduces risk in safety‑critical assemblies by standardizing inspection, testing and manufacturing controls.
• Facilitates compliance with airworthiness and procurement requirements.

Related standards (selected)

• ISO 2859‑1 (sampling procedures, AQL)
• ISO 3452‑1 (penetrant NDT)
• ISO 5855‑2 (MJ thread limit dimensions)
• ISO 9227 (salt spray corrosion testing)
• ISO/TR 13425 and ISO 7870 series (SPC guidance)
• ISO 7961 / ISO 6892‑1 (tensile testing references)

Keywords: ISO 9154:2016, aerospace bolts, MJ threads, nickel‑based alloy, heat‑resistant, strength class 1550 MPa, procurement specification, quality assurance, passivation, SPC.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 9154
Second edition
2016-02-15
Aerospace — Bolts, with MJ threads,
made of heat-resistant nickel-based
alloy, strength class 1 550 MPa —
Procurement specification
Aéronautique et espace — Vis à filetage MJ, en alliage résistant
à chaud à base de nickel, classe de résistance 1 550 MPa —
Spécification d’approvisionnement
Reference number
©
ISO 2016
© 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
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2016 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Quality assurance . 3
4.1 General . 3
4.1.1 Approval of manufacturers . 3
4.1.2 Qualification of bolts . 3
4.1.3 Acceptance of bolts . 3
4.2 Qualification inspection conditions . 3
4.3 Acceptance inspection conditions . 4
4.4 Use of “statistical process control (SPC)” . 4
5 Requirements . 5
Annex A (normative) Passivation treatment .20
Annex B (informative) Cross-sectional areas and formulae for tensile, tension fatigue and
stress rupture loads .21
Annex C (informative) Cross-sectional areas and formulae for double shear loads .23
Bibliography .25
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 20, Aircraft and space vehicles, Subcommittee
SC 4, Aerospace fastener systems.
This second edition cancels and replaces the first edition (ISO 9154:1999), which has been
technically revised.
Annex A forms a normative part of this International Standard. Annexes B and C are for information only.
iv © ISO 2016 – All rights reserved

INTERNATIONAL STANDARD ISO 9154:2016(E)
Aerospace — Bolts, with MJ threads, made of heat-
resistant nickel-based alloy, strength class 1 550 MPa —
Procurement specification
1 Scope
This International Standard specifies the characteristics and quality assurance requirements for
MJ threads bolts made of heat-resisting nickel-base alloy, of strength class 1 550 MPa, for aerospace
construction.
It is applicable whenever it is referenced in a definition document.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 2859-1, Sampling procedures for inspection by attributes — Part 1: Sampling schemes indexed by
acceptance quality limit (AQL) for lot-by-lot inspection
ISO 3452-1, Non-destructive testing — Penetrant testing — Part 1: General principles
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.
3.1
batch
quantity of finished products, manufactured using the same processes, from a single material cast
(single heat of alloy) having the same definition document number, diameter, and length code, heat
treated together to the same specified condition and produced as one continuous run
3.2
inspection lot
quantity of bolts products from a single production batch (3.1) having the same definition document
number
3.3
definition document
document specifying directly or indirectly all the requirements for products
Note 1 to entry: The definition document may be an International Standard, an in-house standard, or a drawing.
3.4
crack
rupture in the material which may extend in any direction and which may be intercrystalline or
transcrystalline in character
3.5
seam
longitudinal open surface defect
3.6
lap
surface defect caused by folding over metal fins or sharp corners and then forming them into the surface
3.7
crevice
hollow area at thread crest
3.8
inclusions
non-metallic particles originating from the material manufacturing process
Note 1 to entry: These particles may be isolated or arranged in strings.
3.9
microstructural shearing
shear banding
V- or U-shaped rippled grain structure immediately below the thread root or chevron-shaped rippled
grain structure within the thread crest
3.10
sampling plan
plan according to which one or more samples are taken in order to obtain information and possibly to
reach a decision, if possible
Note 1 to entry: In this International Standard, each sampling plan defines the number of bolts to be inspected as
1)
a function of the size of the batch and the acceptance number [number of defective items acceptable (Ac)]
3.11
simple random sampling
sampling of n items from a population of N items in such a way that all possible combinations of n items
have the same probability of being chosen
3.12
critical defect
defect that, according to judgement and experience, is likely to result in hazardous or unsafe conditions
for individuals using, maintaining, or depending upon the considered product, or that is likely to
prevent performance of the function of a major end item
3.13
major defect
defect other than critical that is likely to result in a failure or to reduce materially the usability of the
considered product for its intended purpose
3.14
minor defect
defect that is not likely to reduce materially the usability of the considered product for its intended
purpose or that is a departure from established specifications having little bearing on the effective use
or operation of this product
3.15
limiting quality
LQ
a quality level which corresponds to a specified and relatively low probability of
acceptance
Note 1 to entry: It is the limiting lot quality characteristic that the consumer is willing to accept with a low
probability that a lot of this quality would occur.

1) Supplementary information taken from ISO 2859-1.
2 © ISO 2016 – All rights reserved

Note 2 to entry: For the purposes of this International Standard, the limiting quality quoted in Table 4 corresponds
to a probability of acceptance of 10 %.
3.16
acceptable quality limit
AQL
maximum percent defective (or the maximum number of defects per hundred units) that, for purposes
of sampling inspection, can be considered satisfactory as a process average
Note 1 to entry: Variant: Quality level, which in a sampling plan, corresponds to a specified but relatively high
probability of acceptance.
4 Quality assurance
4.1 General
4.1.1 Approval of manufacturers
All parts which are going to be assembled to a flying aircraft, need to be qualified per airworthiness
regulations. The manufacturer of these parts shall have a quality system that complies with EASA /
FAA or an equivalent regulation such as SAE AS 9100 / EN 9100.
Quality documentation for parts produced in accordance with this International Standard, shall be
maintained for a minimum period of 10 years.
The approval of the manufacturer shall be granted by the Certification Authorities, or their appointed
representative, who may be the prime contractor.
4.1.2 Qualification of bolts
2)
The purpose of inspections is to verify that the design and manufacturing conditions of a bolt enable it
to satisfy the requirements of this International Standard.
The qualification shall be granted by the Certification Authorities in the purchaser’s country, or their
appointed representative, who may be the prime contractor.
4.1.3 Acceptance of bolts
The purpose of inspections is to verify, as simply as possible, using a method which is inexpensive,
with the uncertainty inherent in statistical sampling, that the bolts satisfy the requirements of this
International Standard.
They shall be carried out by the manufacturer or under his responsibility.
The manufacturer is responsible for the quality of the bolts manufactured.
4.2 Qualification inspection conditions
Unless otherwise specified, the inspection shall be carried out on the following:
— each type and diameter of bolt;
— 28 bolts selected from a single inspection lot by simple random sampling.
2) In order to simplify the text, the term “inspections” used in this International Standard also refers to “inspections
and tests”.
The test programme may possibly be reduced, or the qualification granted, without inspection: Any
such decision shall be based on the results obtained on similar types and diameters of bolts, provided
that the design and manufacturing conditions are identical.
The inspections shall be repeated on any bolt if the manufacturing conditions have modified.
Table 2 indicates the allocation of bolt sample for the inspections.
4.3 Acceptance inspection conditions
Inspections shall be carried out on each production batch or inspection lot. Bolts from the batch or lot
to be inspected shall be selected by simple random sampling.
Each bolt may be submitted to several inspections, provided that none of characteristics to be verified
has been previously altered during any of these inspections.
The bolts to be subjected to destructive inspections may be those on which non-destructive inspections
have been carried out.
If a more stringent inspection is deemed necessary, all or part of the qualification inspections may be
performed during the acceptance inspections. In this case, the number of bolts submitted is the same as
that submitted for qualification inspection.
Production batches or inspection lots declared unacceptable after the production acceptance
inspections shall be submitted for re-inspection only after all the defective units have been removed
and/or defects have been corrected. In this case, the attribute(s) which caused the rejection shall be
verified using a sample of twice the normal size with the same number of defective items acceptable.
4.4 Use of “statistical process control (SPC)”
When a characteristic is obtained by a controlled statistical process, the manufacturer has the
possibility, in order to declare conformity of the characteristic, of refraining from the final systematic
sampling provided for in this International Standard, if he is capable of formally justifying this choice
by using ISO/TR 13425 and the standards quoted in it as a basis.
This justification will include the following phases:
— analysis of the key characteristics of the product;
— analysis of the risks for each implemented process;
— determination of the parameters and/or characteristics to be respected under SPC;
— determination of the capabilities of each process;
— drawing up an inspection plan and integration in the manufacturing process;
— drawing up of routes and control charts (ISO 7870-1, ISO 7870-2, ISO 7870-3);
— use of control charts for data consolidation;
— determination of the audits to be run and the control to be carried out to ensure reliability of the
device.
To be usable in production, this process shall or should be validated beforehand by the qualifying body,
either during the qualification phase, or a posteriori according to the case, by analysing the justificatory
file and the results of the qualification inspections such as provided for in Clause 5. Such SPC process
not applicable to destructive tests apart from the measurement of the hydrogen content.
4 © ISO 2016 – All rights reserved

5 Requirements
The requirements of this International Standard are given in Table 1 and, unless otherwise specified,
they apply to bolts ready for use. The test temperature, unless otherwise specified, shall be the ambient
temperature. These requirements complement the requirements of all other standards or specifications
referenced in the definition document.
Table 1 — Requirements and test methods
Character- Designa- Sample
Clause Requirement Inspection and test method
a
istic tion size
5.1 Material In accordance with the definition See material standard As re-
document quired
by
semi-fin-
ished
product
5.2 Dimensions In accordance with the definition Standard gauging Q 20
document
A Tables 3
and 4
5.3 Manufactur-
ing
5.3.1 Forging The heads of the bolts shall be According to the route of man- Q
formed by a forging process be- ufacture
fore heat treatment.
The equipment used shall be
The equipment shall ensure an approved.
adequate and uniform tempera-
ture throughout the production
batch.
5.3.2 Heat treat- The forged blanks shall be According to the process Q
ment heat-treated to produce the prop- route
erties required by the definition
The equipment used shall be
document. Blanks shall not be
approved.
heat-treated more than twice.
5.3.3 Removal of If machining is required, it is
surface con- necessary to respect the require-
tamination ments of 5.5.1.
(bearing face
and shank)
5.3.4 Fillet The fillet radius shall be cold Visual examination at a Q 5
between head rolled after heat treatment and suitable magnification of
A Tables 3
and shank machining so as to remove all ×10 to ×20 and dimensional
and 4
visual signs of machining and to check
create superficial cold-working.
The deformation shall not exceed
the values in Figure 1.
The requirements apply on bolts
except on the following:
a) threaded to head bolts;
b) bolts with a nominal diame-
ter <5 mm.
5.3.5 Threads Formed by a single rolling pro- According to the manufactur- Q
cess after full heat treatment ing route
a
Q = Qualification, A = Acceptance.
Table 1 (continued)
Character- Designa- Sample
Clause Requirement Inspection and test method
a
istic tion size
5.3.6 Surface In accordance with the definition ISO 4288 Q 5
roughness document
Visual examination A Tables 3
and 4
5.3.7 Passivation Uncoated finished bolts shall be ISO 9227 Q 5
treatment passivated in accordance with
Visual examination A 100 %
Annex A
After 2 h of salt spray, bolts shall
show no evidence of corrosion or
staining
5.3.8 Surface coat- In accordance with the definition See surface coating standard Q 5
ing document
A Tables 3
and 4
5.4 Mechanical
properties
5.4.1 Tensile See Table 5 On bolts: ISO 7961
stress
The requirements apply to bolts On test specimen: ISO 6892-1
except for the following:
The test specimens to be pro-
a) protruding head bolts of grip duced from the same material
length < twice the nominal shank batch as the bolts and treated
diameter; with them.
b) countersunk head bolts of grip
length < two and a half times the
nominal shank diameter;
c) threaded to head bolts of
overall length < three times the
nominal thread diameter or bolts
having an overall length <18 mm;
d) bolts with a thread
length < one and a half times the
thread nominal diameter;
e) bolts with a nominal diame-
ter < 4 mm.
5.4.1.1 - at ambient Q 5
temperature
A Table 6 or
Table 7
5.4.1.2 - at elevated Applicable to protruding head Q 2
temperature only. Test temperature: 480 °C
a
Q = Qualification, A = Acceptance.
6 © ISO 2016 – All rights reserved

Table 1 (continued)
Character- Designa- Sample
Clause Requirement Inspection and test method
a
istic tion size
5.4.2 Double shear See Table 5. ISO 7961 Q 5
strength
The requirements apply on bolts A Table 6 or
except on the following: Table 7
a) protruding head bolts of grip
length < twice the nominal shank
diameter;
b) countersunk head bolts of grip
length < two and a half times the
nominal shank diameter;
c) bolts with a nominal diame-
ter < 4 mm;
d) threaded to head bolts.
5.4.3 Tension Life ISO 7961 Q 5
fatigue
— mean value: A Table 6
strength
65 000 cycles min.
— individual value:
45 000 cycles min.
130 000 cycles max.
Frequency: 140 Hz max.
Loads: See Table 8.
The requirements apply on bol
...