ISO 18669-1:2004

Internal combustion engines — Piston pins — Part 1: General specifications

ISO 18669-1:2004 specifies the essential dimensional characteristics of piston pins of outer diameter from 8 mm up to 100 mm, for reciprocating internal combustion engines. In addition, it establishes a vocabulary, a pin-type classification, material description based on mechanical properties, common features and quality requirements. It may also be used for piston pins of compressors working under analogous conditions. In certain applications, except road vehicles, and provided that mutual agreement is made between the purchaser and the manufacturer, ISO 18669-1:2004 may be used with suitable modifications.

Moteurs à combustion interne — Axes de pistons — Partie 1: Spécifications générales

General Information

• Status: Withdrawn
• Publication Date: 09-Sep-2004
• Withdrawal Date: 09-Sep-2004
• ICS: 43.060.10 - Engine block and internal components
• Technical Committee: ISO/TC 22 - Road vehicles
• Drafting Committee: ISO/TC 22 - Road vehicles
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 23-Jul-2013

Relations

• Revised: ISO 18669-1:2013 - Internal combustion engines — Piston pins — Part 1: General specifications
• Effective Date: 10-Oct-2009

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 18669-1
First edition
2004-09-01

Internal combustion engines — Piston
pins —
Part 1:
General specifications
Moteurs à combustion interne — Axes de pistons —
Partie 1: Spécifications générales




Reference number
ISO 18669-1:2004(E)
©
ISO 2004

---------------------- Page: 1 ----------------------
ISO 18669-1:2004(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2004
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland

ii © ISO 2004 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 18669-1:2004(E)
Contents Page
Foreword. iv
1 Scope. 1
2 Terms and definitions. 1
2.1 General. 1
2.2 Geometrical and manufacturing features of piston pins. 1
3 Symbols . 2
4 Nomenclature . 3
4.1 Outside, inside and end features . 3
4.2 Outside edge and inside chamfer configurations . 5
5 Codes . 7
6 Designation of piston pins. 7
6.1 Designation elements and order . 7
6.2 Designation examples . 8
7 Piston pin types, dimensions and tolerances. 8
7.1 Manufacturing types . 8
7.2 Dimensions and tolerances . 9
8 Material and heat treatment . 14
8.1 Type of material. 14
8.2 Core hardness l core strength. 15
8.3 Carburised and nitrided case depth. 15
8.4 Surface hardness . 16
8.5 Volume change. 16
9 Common features. 17
9.1 Roughness of surfaces . 17
9.2 Marking of piston pins. 17
9.3 Miscellaneous. 17
10 Quality requirements . 18
10.1 Material characteristics . 18
10.2 Material defects . 18
10.3 Visual defects . 19
Bibliography . 20

© ISO 2004 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 18669-1:2004(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 18669-1 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

iv © ISO 2004 – All rights reserved

---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 18669-1:2004(E)

Internal combustion engines — Piston pins —
Part 1:
General specifications
1 Scope
This part of ISO 18669 specifies the essential dimensional characteristics of piston pins of outer diameter from
8 mm up to 100 mm, for reciprocating internal combustion engines. In addition, it establishes a vocabulary, a
pin-type classification, material description based on mechanical properties, common features and quality
requirements. It may also be used for piston pins of compressors working under analogous conditions.
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 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1 General
2.1.1
piston pin
precision cylindrical component that connects the piston to the connecting rod and has a smooth hard
peripheral surface
2.2 Geometrical and manufacturing features of piston pins
2.2.1 Bore types
2.2.1.1
cylindrical
pin having a straight cylindrical bore
2.2.1.2
centre web
pin inside diameter formed symmetrically from each end leaving a web in the pin centre
NOTE The web is subsequently removed leaving a step as shown in Figure 2.
2.2.1.3
tapered
pin with conical-shaped inside diameter near the ends that reduces the weight of the piston pin
2.2.1.4
machined
pin with inside diameter produced solely by machining
© ISO 2004 – All rights reserved 1

---------------------- Page: 5 ----------------------
ISO 18669-1:2004(E)
2.2.1.5
seamless drawn tube
hollow steel product which does not contain any line junctures resulting from the method of manufacture
2.2.1.6
end web
pin inner diameter formed from one end leaving a web near the opposite end
NOTE The web is punched out. The pin is then drawn over a mandrel and a forming line may result as shown in
Figure 3.
2.2.2 Outside-edge configurations
2.2.2.1
chamfer
outside-edge bevelled feature that is sometimes used to mate with a round retainer ring
NOTE Referred to as “locking chamfer” when a round wire retainer ring is located on the chamfer angle and used to
secure the pin in the piston.
2.2.2.2
form angle
δ
region of outside-edge form that provides a smooth transition to the peripheral surface to facilitate ease of
assembly
2.2.2.3
drop-off
non-functional machining feature that creates a transition between the outside edge and the peripheral
surface
See Figures 6, 7 and 9.
2.2.2.4
inside-edge chamfer
bevelled edge between the bore surface and the end faces of the piston pin
2.2.2.5
gauge point
locating point on the pin outside-edge chamfer from where the gauge diameter (d ) and gauge length (l ) are
5 5
measured
2.2.3 Other features
2.2.3.1
volume change
change detected as a permanent outside-diameter dimensional deviation at reference temperature after being
heated to a test temperature for a specified period of time
2.2.3.2
slag lines
linear flaws of non-metallic inclusions
3 Symbols
For the purposes of this part of ISO 18669, the symbols in Table 1 apply.
2 © ISO 2004 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 18669-1:2004(E)
Table 1 — Symbols
Symbol abbreviation Description
a Wall thickness
b Outside-edge drop-off length
c Outside-edge drop-off height
d Outside diameter
1
d Inside diameter
2
d Tapered bore diameter
3
d Centre-web diameter
4
d Gauge diameter
5
f Outside-edge length
g Outside-edge chamfer length
l Length
1
l Tapered bore length
3
l Centre-web length
4
l Gauge length
5
r Outside-edge radius
R Core strength
m
s End face runout
t Inside-edge chamfer length
α Tapered bore angle
β Outside-edge chamfer angle
δ Outside-edge form angle
H Limit hardness
s
4 Nomenclature
4.1 Outside, inside and end features
Terms commonly used to describe pins with a cylindrical bore are shown in Figure 1.

Key
1 end face d outside diameter
1
2 bore surface d inside diameter
2
3 peripheral surface l length
1
a
Wall thickness.
Figure 1 — Pin with cylindrical bore
© ISO 2004 – All rights reserved 3

---------------------- Page: 7 ----------------------
ISO 18669-1:2004(E)
Terms commonly used to describe pins with a centre web are shown in Figure 2.

Key
1 centre-web radius
l centre-web length
4
d centre-web diameter
4
Figure 2 — Pin with cold-formed centre web
Terms commonly used to describe pins with a cold-formed end-web are shown in Figure 3.

Key
1 end-web forming line
Figure 3 — Pin with cold-formed end web
Terms commonly used to describe pins with a tapered bore are shown in Figure 4.

Key
1 tapered bore surface α tapered bore angle
d tapered bore diameter l tapered bore length
3 3
Figure 4 — Pin with tapered bore
4 © ISO 2004 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 18669-1:2004(E)
4.2 Outside edge and inside chamfer configurations
Terms commonly used to describe the outside edge and inside chamfer configurations are shown in Figure 5.

Key
1 outside-edge radius or chamfer (see Figures 6 and 7)
2 inside-edge chamfer
t inside-edge chamfer length
a
See Figure 6
b
See Figure 7
NOTE This may be used with either a round or rectangular retainer ring.
Figure 5 — Outside-edge configuration
Terms commonly used to describe the chamfered outside-edge configuration and outside-edge drop-off are
shown in Figure 6a).
Terms commonly used to describe double-chamfered outside-edge configurations are shown in Figure 6b).

Key Key
b outside-edge drop-off length f outside-edge length
f outside-edge length g outside-edge chamfer length
c outside-edge drop-off height
δ outside-edge form angle
β outside-edge chamfer angle β outside-edge chamfer angle
a)  Chamfer and drop-off b)  Double-chamfered edge
NOTE Outside-edge drop-off may be used with chamfered, double-chamfered, or radiused outside-edge
configurations.
Figure 6 — Detail X of Figure 5
© ISO 2004 – All rights reserved 5

---------------------- Page: 9 ----------------------
ISO 18669-1:2004(E)
Terms commonly used to describe radiused outside-edge configurations are shown in Figure 7.

Key
r outside-edge radius
f outside-edge length
δ outside-edge form angle
Figure 7 — Detail Y of Figure 5
Terms commonly used to describe chamfer-locking outside-edge configurations are shown in Figures 8 and 9.

Key
1 gauge points
l gauge length
5
d gauge diameter
5
Figure 8 — Chamfer-locking outside edge for round retainer ring

Key
1 gauge point
d gauge diameter
5
f outside-edge length
g outside-edge chamfer length
l gauge length
5
Figure 9 — Detail Z of Figure 8
6 © ISO 2004 – All rights reserved

---------------------- Page: 10 ----------------------
ISO 18669-1:2004(E)
5 Codes
Codes used for piston pins shall be as given in Table 2 with their explanatory descriptions.
Table 2 — Codes and descriptions
Relevant
Code Description ISO 18669-1
clause
P1…P6 Pin-type classification according to manufacturing method of the pin bore 7.1
X Piston pins in combination with needle bearing  8.3
F1, F2 Outside-edge configuration tolerance class 7.2.4
K Carburising steel class K 8.1 / 8.2
S Carburising steel class S 8.1 / 8.2
L Carburising steel class L 8.1 / 8.2
M Carburising steel class M 8.1 / 8.2
N Nitriding steel class N 8.1 / 8.2
V Piston pins with limited volume change 8.3 / 8.4 / 8.5
R1, R2 Peripheral surface roughness class 9.1.1
G Chamfer-locking outside-edge configuration (gauge point) 6.2 / 7.2.4
R Outside-edge radiused 7.2.4 / 6.1.2
C1 Outside-edge chamfered 7.2.4
C2 Outside-edge double chamfered 7.2.4
LA, LB Length tolerance class 7.2.3
MM Manufacturer’s mark 9.2
TC Piston pins with bore surface cold formed 7.2.6
6 Designation of piston pins
6.1 Designation elements and order
To designate piston pins, the following details shall be given, in the order shown below. The codes given in
Table 2 shall be used.
6.1.1 Mandatory elements
The following mandatory elements shall constitute the designation of a piston pin:
 designation, i.e., piston pin;
 number of International Standard: ISO 18669;
 type of piston pin, e.g. P1;
 hyphen;
 size of piston pin, d × d × l or d / d − α × d × l for a pin with tapered bore;
1 2 1 1 3 2 1
 hyphen;
 material code, e.g. L.
© ISO 2004 – All rights reserved 7

---------------------- Page: 11 ----------------------
ISO 18669-1:2004(E)
6.1.2 Additional elements
The following optional elements may be added to the designation of a piston pin; in this case they shall be
...