ISO 7554-3:2026

International
Standard
ISO 7554-3
First edition
Surgical instruments — Terms,
2026-06
measuring methods and test
methods —
Part 3:
Test methods
Instruments chirurgicaux — Termes, méthodes de mesurage et
méthodes d'essai —
Partie 3: Méthodes d'essai
Reference number
© ISO 2026
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Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements and tests . 1
4.1 General information.1
4.1.1 Form and type .1
4.1.2 Surface .2
4.2 Scalpels and knives .2
4.2.1 Form and type .2
4.2.2 Test material .2
4.2.3 Functional test.2
4.3 Scissors and shears .2
4.3.1 Form and type .2
4.3.2 Functioning .3
4.3.3 Test material .4
4.3.4 Procedure for functional test .4
4.4 Chisels, osteotomes, raspatories, curettes and sharp spoons .5
4.4.1 Form and type .5
4.4.2 Test material .5
4.4.3 Procedure for functional test for raspatories, curettes and sharp spoons .5
4.4.4 Procedure for functional test for chisels and osteotomes .5
4.5 Conchotomes and rongeurs . .5
4.5.1 Form and type .5
4.5.2 Test material for through cutting conchotomes and rongeurs .6
4.5.3 Procedure for functional test for through cutting conchotomes and rongeurs .6
4.5.4 Test material for non-cutting (gripping) conchotomes and rongeurs .6
4.5.5 Procedure for functional test for non-cutting (gripping) conchotomes and
rongeurs .6
4.6 Bone-cutting forceps, gouges and bone punches .6
4.6.1 Form and type .6
4.6.2 Test material .6
4.6.3 Procedure for functional test .6
4.7 Tweezers .7
4.8 Retractors, self-retaining retractors, abdominal retractors .7
4.9 Probes, ligature needles and elevatories .7
4.10 Ring forceps and clamps .7
4.10.1 General information .7
4.10.2 Elasticity test .7
4.10.3 Ring forceps with atraumatic serration .8
4.11 Needle holders .8
4.11.1 General information .8
4.11.2 Jaw test .9
4.11.3 Test of the functioning of the profile .9
4.11.4 Elasticity test .9
4.12 Branch forceps .10
5 General test methods .10
5.1 Functional test .10
5.2 Boiling test .10
5.3 Hardness test .10
6 Marking . .10
Annex A (informative) Example calculations of Müller indices .11

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 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).
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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 170, Surgical instruments.
A list of all parts in the ISO 7554 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
International Standard ISO 7554-3:2026(en)
Surgical instruments — Terms, measuring methods and test
methods —
Part 3:
Test methods
1 Scope
This document defines test methods for surgical standard instruments. This document does not cover
instruments for use on the central nervous system and on the central cardiovascular system.
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 3738-1, Hardmetals — Rockwell hardness test (scale A) — Part 1: Test method
ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 6508-1, Metallic materials — Rockwell hardness test — Part 1: Test method
1)
ISO 7554-1, Surgical instruments — Terms, measuring methods and tests — Part 1: Vocabulary
ISO 13402, Surgical and dental hand instruments — Determination of resistance against autoclaving, corrosion
and thermal exposure
ISO 20417, Medical devices — Information to be supplied by the manufacturer
3 Terms and definitions
1)
For the purposes of this document, the terms and definitions given in ISO 7554-1 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/
4 Requirements and tests
4.1 General information
4.1.1 Form and type
The instruments shall not deform irreversibly, with the exception of flexible instruments, and shall not
break during use for their intended purpose.
1) Under preparation. Stage at the time of publication: ISO/FDIS 7554-1.

There shall not be any sharp edges or corners, except for the cutting edges on the working end.
Hollow handles shall be securely connected to the working parts of the instruments, without openings or
hearable residues inside the handles during movement.
Matching parts shall have the same shape in terms of size and symmetry.
4.1.2 Surface
The surface shall be free of burrs, cracks, joint gaps and pores, scars, orange peel, scratches, machining
marks or other damage as well as visually noticeable oil residues and machining materials, traces of powder,
discolourations, annealing colours, stains, machining residues and corrosion or other contamination.
Excluded from this are vapour-permeable medical oils that may be applied to joints and functional and
gliding surfaces.
The inspection of the instrument surface shall be carried out through direct visual inspection. During
the visual inspection, the inspection specimen or the inspection surface shall be sufficiently illuminated.
During visual inspection, the beam path between the eye of the tester and the inspection surface shall not
be interrupted. This inspection is carried out without any auxiliary tools, e.g. microscopes or magnifying
glasses.
The visual inspection shall be performed from a person with normal eyesight or corrected vision.
NOTE For more information on visual testing, see EN 13018.
Instruments can be manufactured with different finishes. Examples are:
— mat finish
Examples of mechanical processing: glass or ceramic beads blasting, with brushes on a grinding fleece
disk;
— mirror polished finish: see ISO 7151 and ISO 7741.
Examples of mechanical processing: polishing on a buffing wheel or slide grinding.
Examples of chemical or electrochemical processing, or both: electropolishing.
4.2 Scalpels and knives
4.2.1 Form and type
The blade shall be ground and honed.
4.2.2 Test material
Polyethylene film (PE film) with a thickness of 50 µm to 100 µm shall be used as the test material.
4.2.3 Functional test
Scalpels and knives are tested by cutting through the test material. The cut shall be made with 2/3 of the
distal end of the blade. The test material shall be cut through with a clean cut.
4.3 Scissors and shears
4.3.1 Form and type
The scissors shall not get caught during cutting.
The blades shall be free of any imperfections and burrs.

The cutting edge-holding properties of scissor blades may be improved by applying additional materials (e.g.
cast or sintered carbides) using suitable joining processes.
The permissible hardness difference between the blades shall not exceed 4 HRC (Hardness Rockwell, see
ISO 6508-1). The hardness of scissors with blades with improved edge-holding properties shall be 650 HV 10
(Hardness Vickers, see ISO 6507-1) as a minimum. The permissible difference between the blades in the area
with wear protection shall not exceed 50 HV 10.
4.3.2 Functioning
The Müller index M specifies the thickness of the test material for a particular pair of scissors that is used
to test the functionality of the scissors. The dimensionless Müller Index M is defined in accordance with
Formula (1):
l
M= (1)
ba·
where
M is the Müller index;
l is the length tip to joint;
b is the joint width;
a is the joint thickness.
The variables are given in Figure 1.
The length l of the cutting edge cannot be used for the definition of the Müller factor as it cannot be explicitly
defined for some types of scissors, e.g. Metzenbaum.
Scissors with flat knob, hook knob, probe knob or ball knob are exceptions to this. For these scissors, the
short scissor blade shall be considered as dimension l .
Scissors with an offset tip, e.g. Stevens tenotomy scissors, shall be
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