ISO 18669-2:2004

INTERNATIONAL ISO
STANDARD 18669-2
First edition
2004-09-01

Internal combustion engines — Piston
pins —
Part 2:
Inspection measuring principles
Moteurs à combustion interne — Axes de pistons —
Partie 2: Principes de mesure pour le contrôle




Reference number
ISO 18669-2:2004(E)
©
ISO 2004

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ISO 18669-2:2004(E)
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ii © ISO 2004 – All rights reserved

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ISO 18669-2:2004(E)
Contents Page
Foreword. iv
1 Scope. 1
2 Normative references . 1
3 Measuring principles . 2
3.1 General measuring conditions . 2
3.2 Characteristics and measuring principles . 2

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ISO 18669-2:2004(E)
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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 18669-2 was prepared by Technical Committee ISO/TC 22, Road vehicles.
ISO 18669 consists of the following parts, under the general title Internal combustion engines — Piston pins:
Part 1: General specifications
Part 2: Inspection measuring principles

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INTERNATIONAL STANDARD ISO 18669-2:2004(E)

Internal combustion engines — Piston pins —
Part 2:
Inspection measuring principles
1 Scope
This part of ISO 18669 defines the measuring principles to be used for measuring piston pins; it applies to
piston pins from 8 mm up to and including 100 mm outside diameter for reciprocating internal combustion
engines and compressors.
In certain applications, except road vehicles, and provided that mutual agreement is made between the
purchaser and the manufacturer, this part of ISO 18669 may be used with suitable modifications.
2 Normative references
The following referenced documents are indispensable for the application 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 1101, Geometrical Product Specifications (GPS) — Geometrical tolerancing — Tolerances of form,
orientation, location and run-out
ISO 2639, Steels — Determination and verification of the depth of carburized and hardened cases
ISO 4287, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms, definitions
and surface texture parameters
ISO 4288, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Rules and
procedures for the assessment of surface texture
ISO 9934 (all parts), Non-destructive testing — Magnetic particle testing
ISO 6506 (all parts), Metallic materials — Brinell hardness test
ISO 6507 (all parts), Metallic materials — Vickers hardness test
ISO 6508 (all parts), Metallic materials — Rockwell hardness test
QS 9000, Quality Systems Requirements
ISO 14104:1995, Gears — Surface temper etch inspection after grinding
ISO 14253 (all parts), Geometrical Product Specifications (GPS) — Inspection by measurement of work
pieces and measuring equipment
ISO 18669-1:2004, Internal combustion engines — Piston pins — Part 1: Specifications
EN 583 (all parts), Non-destructive testing — Ultrasonic examination
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ISO 18669-2:2004(E)
3 Measuring principles
3.1 General measuring conditions
The following general requirements are applicable to all measuring principles unless otherwise specified:
a) Measurements shall be made using instruments with a resolution not exceeding 10 % of the tolerance of
the dimension being measured.
b) Concerning “Measuring uncertainty”, take notice of ISO 14253.
c) Concerning “Acceptance of gauge repeatability and reproducibility (% R & R)” take notice of QS 9000.
d) The reference temperature for outside-diameter measurements shall be 21 ± 1 °C.
3.2 Characteristics and measuring principles
Characteristic Measuring principle
3.2.1 Outside diameter d
1
Diameter of the outer surface measured at Method A: Reference method.
any point excluding areas of edge drop-off,
b (see Figure 10, ISO 18669:2004).
Measure with a precision calliper having spherical measuring
probes each of radius 1,5 mm min. exerting a measuring force
of approximately 1 N (see Figure 1).

Figure 1 — Outside-diameter measuring principle
Other methods: All methods which are able to guarantee the
required measurement uncertainty. Method must be agreed to
between manufacturer and client.
Measurement uncertainty:
± 0,000 5 mm in accordance with ISO 14253
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ISO 18669-2:2004(E)
Characteristic Measuring principle
3.2.2 Cylindricity of the outside diameter d
1
Geometric form of the peripheral surface Method A:
excluding areas of edge drop-off, b.
Record and evaluate a macro-form diagram of opposite sides in
Characteristics measured in the axial the axial direction (profile lines) or by recording and evaluating
direction are taper, convexity, concavity of a multiple polar diagram (measuring in min. 3 planes, near
and waviness. both ends and centre of pin).
(Reference: ISO 1101)
Method B:
Outside diameter, d measured in a V-block by diametral
1
gauging at centre of piston pin and at distance l from both
x
ends and calculating the difference rate (see Figure 2).
Measuring sensor: according to 3.2.1.
l = 0,15 × d   d W 50 mm
x 1 1
l = 0,10 × d   d < 50 mm
x 1 1

Figure 2 — Cylindricity measuring principle
3.2.3 Circularity of the outside diameter d
1
All deviations of the peripheral surface from Recording and evaluation of a macro-form diagram in the
circularity such as waviness, ovality and circumferential direction and at several planes (polar diagram).
spherical-triangular forms.
(Reference: ISO 1101)
3.2.4 Edge drop-off b, c
Geometric form of the peripheral surface at Record and evaluate a macro-form diagram on both ends in the
the outside edges. axial direction (profile lines), (see Figure 10, ISO 18669-
1:2004).
3.2.5 Inside diameter d , d
2 4
Diameter of the bore measured at any Measured with inside measuring devices.
point.
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ISO 18669-2:2004(E)
Characteristic Measuring principle
3.2.6 Concentricity of inside diameter ID relative to outside diameter OD
Difference between the maximum and Method A:
minimum dimensions of the wall thickness
(a) as measured in a plane perpendicular
Measured with a thickness gauge (e.g. dial calliper or
to the peripheral surface. comparable gauges) (see Figure 3).
(Reference: ISO 1101)

Figure 3 — Inside-diameter concentricity (Radial runout)
Method B:
Measured with a calliper or probe-indicator by 360° rotation in a
V-block (see Figure 4).

Figure 4 — Wall-thickness measuring principle
3.2.7 Length l
1
Maximum dimension measured between Method A:
two planes perpendicular to the peripheral
surface.
Measured between two planes parallel to each other and
perpendicular to the outside surface (see Figure 5).


Figure 5 — Length measuring principle
Other methods:
All methods, which are able to guarantee the required
measurement uncertainty and take account of runout.
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ISO 18669-2:2004(E)
Characteristic Measuring principle
3.2.8 Gauge length l
5
Dimension between the gauge points The pin is put between two ring gauges perpendicular to the
measured perpendicular to the peripheral outside surface, with inside diameters d . The sharp edges of
5
surface. these gauges measure from contact point to contact point. This
“assembly” of pin and two rings is put in a hei
...