SIST EN ISO 2738:2026

SLOVENSKI STANDARD
01-marec-2026
Sintrane kovine brez trdin - Prepustne sintrane kovine - Ugotavljanje gostote,
vsebnosti olja in odprte poroznosti (ISO 2738:2026)
Sintered metal materials, excluding hardmetals - Permeable sintered metal materials -
Determination of density, oil content and open porosity (ISO 2738:2026)
Sintermetalle, ausgenommen Hartmetalle - Durchlässige Sintermetalle - Bestimmung der
Dichte, des Tränkstoffgehaltes und der offenen Porosität (ISO 2738:2026)
Matériaux métalliques frittés, à l'exclusion des métaux-durs - Matériaux métalliques
frittés perméables - Détermination de la masse volumique, de la teneur en huile et de la
porosité ouverte (ISO 2738:2026)
Ta slovenski standard je istoveten z: EN ISO 2738:2026
ICS:
77.160 Metalurgija prahov Powder metallurgy
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 2738
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2026
EUROPÄISCHE NORM
ICS 77.160 Supersedes EN ISO 2738:1999
English Version
Sintered metal materials, excluding hardmetals -
Permeable sintered metal materials - Determination of
density, oil content and open porosity (ISO 2738:2026)
Matériaux métalliques frittés, à l'exclusion des métaux- Sintermetalle, ausgenommen Hartmetalle -
durs - Matériaux métalliques frittés perméables - Durchlässige Sintermetalle - Bestimmung der Dichte,
Détermination de la masse volumique, de la teneur en des Tränkstoffgehaltes und der offenen Porosität (ISO
huile et de la porosité ouverte (ISO 2738:2026) 2738:2026)
This European Standard was approved by CEN on 5 January 2026.

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, Türkiye 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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 2738:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 2738:2026) has been prepared by Technical Committee ISO/TC 119 "Powder
metallurgy" in collaboration with CCMC.
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 July 2026, and conflicting national standards shall be
withdrawn at the latest by July 2026.
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 ISO 2738:1999.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations 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, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 2738:2026 has been approved by CEN as EN ISO 2738:2026 without any modification.

International
Standard
ISO 2738
Fourth edition
Sintered metal materials, excluding
2026-01
hardmetals — Permeable sintered
metal materials — Determination
of density, oil content and open
porosity
Matériaux métalliques frittés, à l'exclusion des métaux-durs —
Matériaux métalliques frittés perméables — Détermination de la
masse volumique, de la teneur en huile et de la porosité ouverte
Reference number
ISO 2738:2026(en) © ISO 2026
ISO 2738:2026(en)
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 2738:2026(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and designations . 2
5 Test procedures . 2
6 Equipment . 3
7 Test piece . 3
8 Test procedures . 4
8.1 Determination of the initial mass of the test piece .4
8.2 Removal of oil from the test piece by solvent extraction.4
8.3 Determination of the mass of the dried test piece.4
8.4 Impregnation with oil and surface coating .4
8.4.1 Full impregnation (for determination of the open porosity) .4
8.4.2 Partial impregnation (suitable for determination of the volume) .5
8.4.3 Surface coating methods (suitable for determination of the volume) .5
8.5 Determination of the mass of the fully impregnated test piece .5
8.6 Determination of the volume of the test piece .5
9 Expression of results . 9
9.1 Density .9
9.2 Oil content .9
9.3 Open porosity .9
10 Precision of dry density determination . 9
11 Test report .11
Bibliography .12

iii
ISO 2738:2026(en)
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 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)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 119, Powder metallurgy, Subcommittee SC 3,
Sampling and testing methods for sintered metal materials (excluding hardmetals), in collaboration with the
European Committee for Standardization (CEN), in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This fourth edition cancels and replaces the third edition (ISO 2738:1999), which has been technically
revised.
The main change is as follows:
— Clause 10 “Precision” revised.
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
International Standard ISO 2738:2026(en)
Sintered metal materials, excluding hardmetals — Permeable
sintered metal materials — Determination of density, oil
content and open porosity
1 Scope
This document specifies methods for determining the density (dry density or fully impregnated density), oil
content (related to test piece volume and related to open porosity) and open porosity of permeable sintered
metal materials.
This document applies in particular to porous metal bearings and to structural parts produced by pressing
and sintering metal powders.
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 758, Liquid chemical products for industrial use — Determination of density at 20 degrees C
ISO 13944, Lubricated metal-powder mixes — Determination of lubricant content — Soxhlet extraction method
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
density
mass, divided by the volume
3.2
dry density
mass of the test piece, after oil extraction and drying, divided by the volume of the test piece
3.3
fully impregnated density
wet density
mass of the test piece, after full impregnation, divided by the volume of the test piece
3.4
oil content related to test piece volume
volume of oil contained in the sample, divided by the volume of the test piece, multiplied by a volume fraction
of 100 %
ISO 2738:2026(en)
3.5
oil content related to open porosity
volume of oil contained in the test piece, divided by the volume of the open porosity, multiplied by a volume
fraction of 100 %
3.6
open porosity
volume of oil after full impregnation divided by the volume of the test piece, multiplied by a volume fraction
of 100 %
3.7
volume
total volume of the test piece including the pores
4 Symbols and designations
Table 1 — Symbols and designations
Symbol Designation Unit
m Initial mass of the test piece g
m Mass of the test piece after oil extraction and drying g
m Mass of the fully impregnated test piece g
m Mass of the fully or partially impregnated test piece plus supporting device (for g
a
example suspension wire) weighed in air
m Mass of the fully or partially impregnated test piece plus supporting device (for g
w
example suspension wire) weighed in water
V Volume of the test piece cm
ρ Density of the water used g/cm
w
a 3
ρ Density of the oil initially in the test piece g/cm
a 3
ρ Density of the impregnating oil used g/cm
a
The oil density is assumed to be known or, if not, it shall be determined in accordance with ISO 758.
5 Test procedures
Depending upon which of the properties are to be determined, some or all of the test procedures in Clause 8
are carried out. Table 2 shows the test procedures that are carried out f
...