ISO 18487-1:2025

International
Standard
ISO 18487-1
Second edition
Aerospace series — Titanium tube
2025-07
for 35 MPa operating pressure —
Part 1:
Inch series
Série aérospatiale — Tubes en titane — Pression de service :
35 MPa —
Partie 1: Série en inches
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Dimensions . 2
5 Tolerances . 2
6 Technical requirements . 3
6.1 General .3
6.2 Composition .3
6.3 Melting practice .3
6.4 Heat treatment and delivery condition.3
6.5 Tensile properties .3
6.6 Microstructure .4
6.6.1 General .4
6.6.2 Grain size .4
6.6.3 Contractile strain ratio (CSR).4
6.7 Surface condition and texture .4
6.7.1 Surface treatment .4
6.7.2 Surface condition .4
6.7.3 Surface texture, R .5
a
6.8 Ultrasonic inspection.5
6.9 Flarability . .5
6.9.1 General .5
6.9.2 Surface contamination .5
6.10 Bending .7
6.11 Flattening .7
6.12 Deformation under pressure test .7
6.13 Impulse pressure fatigue test .8
6.13.1 General .8
6.13.2 Proof test .8
6.13.3 Pressure impulse test .8
6.13.4 Additional test .11
6.13.5 Ultimate (as per CS 25.1435) and burst test .11
7 Quality assurance .12
8 Preparation for delivery .12
8.1 Marking . 12
8.2 Packing . 12
Bibliography .13

iii
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,
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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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
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This document was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee
SC 10, Aerospace fluid systems and components.
This second edition cancels and replaces the first edition (ISO 18487-1:2017), of which it constitutes a minor
revision.
The changes are as follows:
— the normative reference to ISO 4287, which is withdrawn, has been replaced by ISO 21920-2;
— the normative reference to ISO 8575:2016, which is withdrawn, has been replaced by ISO 8575:2024.
A list of all the parts in the ISO 18487 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
This document is intended to harmonize the technical requirements for titanium tubes used in aerospace
with design operating pressure of 35 MPa.
It is noted that, while ISO standards should normally refer only to SI units, large segments of the aerospace
industry refer to other measurement systems as a matter of common working practice. The mention of “inch
series” in the title of this document reflects this. It recognizes the fact that the nominal sizes referred to
in the document, which are in common use in the aerospace industry, were originally defined in terms of
fractional inches.
Although the tube sizes were originally defined, and are frequently referred to, in terms of non-SI units, all
dimensions used in this document are in SI units with inch units given in addition for the convenience of
those users more familiar with these.
It is further noted that the standard ISO decimal symbol “,” (comma) is not used as common working practice
for inch dimensions. A decimal point is used in the inch dimensions in this document as in many other
aerospace standards.
NOTE The use of non-SI units and the decimal point in this document does not constitute general acceptance of
measurement systems other than SI within International Standards.

v
International Standard ISO 18487-1:2025(en)
Aerospace series — Titanium tube for 35 MPa operating
pressure —
Part 1:
Inch series
1 Scope
This document is applicable to seamless tubing of circular cross-section made from titanium alloy and
intended for use primarily in systems with system operating pressure of 35 MPa (5 080 psi) (Pressure Class
J), but usage is not limited to such applications.
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.
ISO 21920-2, Geometrical product specifications (GPS) — Surface texture: Profile — Part 2: Terms, definitions
and surface texture parameters
ISO 6772, Aerospace — Fluid systems — Impulse testing of hydraulic hose, tubing and fitting assemblies
ISO 8492, Metallic materials — Tube — Flattening test
ISO 8575:2024, Aerospace series — Fluid systems — Hydraulic system tubing
ISO 10583, Aerospace fluid systems — Test methods for tube/fitting assemblies
ISO 12573, Aircraft — Tubing tolerances — Inch series
EN 2003-010, Aerospace series — Titanium and titanium alloys — Test methods — Part 010: Sampling for
determination of hydrogen content
EN 3718, Aerospace series — Test method for metallic materials — Ultrasonic inspection of tubes
AS 4076, Contractile strain ratio testing of titanium hydraulic tubing
AMS 2634, Ultrasonic inspection, thin wall metal tubing superseding
ASTM E112, Standard test methods for determining average grain size
ASTM E1409, Standard test method for determination of oxygen and nitrogen in titanium and titanium alloys by
inert gas fusion
ASTM E1941, Standard test method for determination of carbon in refractory and reactive metals and their
alloys by combustion analysis
ASTM E1447, Standard test method for determination of hydrogen in titanium and titanium alloys by the inert
gas fusion thermal conductivity/infrared detection method
ASTM E2371, St
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