ISO 6626-3:2019

Internal combustion engines — Piston rings — Part 3: Coil-spring-loaded oil control rings made of steel

This document specifies the essential dimensions of coil-spring-loaded oil control rings made of steel, of piston ring types SOR (with R-shaped groove) and SOV (with V-shaped groove). This document applies to coil-spring-loaded oil control rings made of steel with a diameter from 60 mm up to and including 160 mm for reciprocating internal combustion engines. It can also be used for piston rings in compressors working under analogous conditions.

Moteurs à combustion interne — Segments de piston — Partie 3: Segments racleurs régulateurs d'huile, en acier, mis en charge par ressort hélicoïdal

General Information

• Status: Published
• Publication Date: 21-Sep-2019
• ICS: 43.060.10 - Engine block and internal components
• Technical Committee: ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
• Drafting Committee: ISO/TC 22/SC 34/WG 4 - Piston rings
• Current Stage: 6060 - International Standard published
• Start Date: 22-Sep-2019
• Due Date: 25-Oct-2018
• Completion Date: 22-Sep-2019

Relations

• Revises: ISO 6626-3:2008 - Internal combustion engines — Piston rings — Part 3: Coil-spring-loaded oil control rings made of steel
• Effective Date: 05-Nov-2015
• Consolidated By: ISO 23402-1:2020 - Dentistry — Portable dental equipment for use in non‐permanent healthcare environment — Part 1: General requirements
• Effective Date: 06-Jun-2022

Standards Content (Sample)

Deleted: /PRF
ISO 6626-3:2019(E)
ISO TC 22/SC34/WG 4
Secretariat: DIN
Internal combustion engines — Piston rings — Part 3: Coil-spring-loaded oil control
rings made of steel

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ISO 6626-3:2019 (E)
© ISO 2019
All rights reserved. Unless otherwise specified, 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
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.
© ISO 2019 – All rights reserved 3

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ISO 6626-3:2016(E)
Contents
Foreword . 7
Introduction. 8
1  Scope . 9
2  Normative references . 9
3  Terms, definitions and symbols . 9
3.1  Symbols . 9
4  Piston ring types and designation examples . 10
4.1  Type SOR — Steel oil control rings with R‐shaped groove . 10
4.1.1  General features and dimensions . 10
Figure 1 — General features and dimensions of piston ring type SOR . 10
4.1.2  Designation . 10
4.2  Type SOV — Steel oil control rings with V‐shaped groove . 11
4.2.1  General features and dimensions . 11
Figure 2 — General features and dimensions of piston ring type SOV . 11
4.2.2  Designation . 11
5  Common features . 11
5.1  Ring width h and radial wall thickness a . 11
1 1
Table 1 — Ring width h and radial wall thickness a . 11
1 1
5.2  Land width h . 12
5
Table 2 — Land width h . 12
5
5.3  Land angle α, β . 12
Table 3 — Land angle α, β . 12
5.4  Land spacing B . 12
3
Table 4 — Land spacing B . 12
3
5.5  Slot sizes . 13
Table 5 — Standard slot sizes . 13
Figure 3 — Arrangement of slots . 13
5.6  Nitrided surface . 13
Table 6 — Nitrided case depth of peripheral surface and sideface . 13
5.7  PVD coating thickness of peripheral surface . 14
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ISO 6626-3:2019 (E)
Table 7 — PVD coating thickness of peripheral surface. 14
5.8  Nominal contact pressure and tangential force . 14
5.8.1  Nominal contact pressure . 14
Table 8 — Nominal contact pressure classes . 14
5.8.2  Actual tangential force, Ft, and tolerance . 14
5.8.3  Normalized tangential force, F . 14
N
5.9  Tolerance of tangential force Ft . 15
Table 10 — Tolerance of tangential force F . 15
t
6  Coil springs . 15
6.1  Types of coil spring . 15
Figure 4 — Type CSN coil spring . 15
Figure 5 — Type CSG coil spring . 16
Figure 6 — Type CSE coil spring . 16
Figure 7 — Position of area with small pitch . 17
6.2  Coil‐spring excursion (extended gap) . 17
Figure 8 — Coil-spring excursion. 17
Table 11 — Coil-spring excursion . 17
6.3  Position of coil spring gap and fixing . 18
6.4  Material . 18
7  Type SOR . 18
Table 12 — Tolerance and calculation criteria on a4, a13, a17, d14, d7 and a12 for type SOR . 18
8  Type SOV . 18
Table 13 — Tolerance and calculation criteria on a , a , a , d and a for type SOV . 18
4 13 17 7 12
9  Dimensions . 19
Table 14 — Index of Tables 15 to 22 . 19
Table 15 — Recommended nominal tangential force of ring type SOR-S (h = 1,5 mm) . 19
1
Table 16 — Recommended nominal tangential force of ring type SOR-S (h = 2,0 mm and
1
h = 2,5 mm) . 20
1
Table 17 — Recommended nominal tangential force of ring type SOR-S and SOR-L
(h = 3,0 mm) . 22
1
Table 18 — Recommended nominal tangential force of ring type SOR-S and SOR-L
(h = 4,0 mm; nominal diameters d < 125 mm) . 24
1 1
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ISO 6626-3:2016(E)
Table 19 — Recommended nominal tangential force of ring type SOR-S and SOR-L
(h = 4,0 mm; nominal diameters d ≥ 125 mm) . 26
1 1
Table 20 — Recommended nominal tangential force of ring type SOV-S and SOV-L
(h = 3,0 mm) . 28
1
Table 21 — Recommended nominal tangential force of ring type SOV-S and SOV-L
(h = 4,0 mm; nominal diameters d < 125 mm) . 29
1 1
Table 22 — Recommended nominal tangential force of ring type SOV-S and SOV-L
(h = 4,0 mm; nominal diameters d ≥ 125 mm) . 31
1 1
Bibliography . 33
6 © ISO 2019 – All rights reserved

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ISO 6626-3:2019 (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.
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).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
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 22, Road vehicles, Subcommittee SC 34,
Propulsion, powertrain and powertrain fluids.
This second edition cancels and replaces the first edition (ISO 6266‐3:2008), which has been technically
revised. The main changes compared to the previous edition are as follows:
— added subclause 5.8.2, Actual tangential force, .F and tolerance;
t
— added subclause 5.8.3, Normalized tangential force, FN;
— added Table 9, Normalized tangential forces, F;
N
— raised table numbers by one from Table 9 onward;
— made editorial changes to Table 16.
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.
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ISO 6626-3:2016(E)
Introduction
ISO 6626 (all parts) is one of a series of International Standards dealing with piston rings for
reciprocating internal combustion engines. Others are ISO 6621 (all parts), ISO 6622 (all parts),
ISO 6623, ISO 6624 (all parts), ISO 6625 and ISO 6627 (see Clause 2 and Bibliography).
The common features and dimensional tables presented in this document constitute a broad range of
variables and, in selecting a particular ring type, the designer will bear in mind the conditions under
which it will be required to operate.
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ISO 6626-3:2016 (E)
Internal combustion engines — Piston rings — Part 3: Coil-
spring-loaded oil control rings made of steel
1 Scope
This document specifies the essential dimensions of coil‐spring‐loaded oil control rings made of steel, of
piston ring types SOR (with R‐shaped groove) and SOV (with V‐shaped groove).
This document applies to coil‐spring‐loaded oil control rings made of steel with a diameter from 60 mm
up to and including 160 mm for reciprocating internal combustion engines. It can also be used for
piston rings in compressors working under analogous conditions.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and symbols
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1 Symbols
a1 radial wall thickness
a groove depth
4
a radial thickness over coil spring
12
a groove depth and bridge
13
Deleted: a14
a17 external land depth
B land spacing
3
c slot width
1
d nominal diameter (nominal bore diameter)
1
d7 coil‐spring diameter
d coil‐spring groove diameter for type SOR
14
f coil‐spring excursion
1
F tangential force
t
h ring width
1
h land width
5
p contact pressure
0
s closed gap
1
w1 slot length
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ISO 6626-3:2016(E)
w slot spacing
3
α land angle inside
β land angle outside
θ groove angle for type SOV
NOTE These symbols (including associated indices) are in accordance with the symbols used in ISO 6621 (all
parts), ISO 6622 (all parts), ISO 6623, ISO 6624 (all parts), ISO 6625, ISO 6627 and other parts of the ISO 6626
series.
4 Piston ring types and designation examples
4.1 Type SOR — Steel oil control rings with R-shaped groove
4.1.1 General features and dimensions
Figure 1 shows the general features and dimensions of piston ring type SOR.
Dimensions in millimetres
Deleted:
NOTE 1 For definitions of symbols, see
Clause 3.¶
Key
NOTE 2 For dimensions, see Tables 3,
4, 5, 11, 14, 15, 16 and 17.¶
1 reference plane
NOTE 1 For definitions of symbols, see Clause 3. Formatted: Font:
NOTE 2 For dimensions, see Tables 1, 2, 3, 4, 5, 11, 12, 14, 15, 16, 17, 18 and 19. Formatted: Font:
Figure 1 — General features and dimensions of piston ring type SOR
4.1.2 Designation
EXAMPLE A coil‐spring‐loaded oil control ring with R‐shaped groove (SOR), a radial wall thickness
class = small (S), of nominal diameter d = 100 mm (100), a nominal ring width h = 3 mm (3), a land width
1 1
h = 0,20 mm (0,20), made of steel MC65 (MC65), a nitrided depth of 0,030 mm min. (NT030), coil spring with
5
reduced heat set (WF), and variable pitch with coil diameter d ground (CSE), medium nominal contact pressure
7
p = 1,5 MPa (PN1,5):
0
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ISO 6626-3:2016 (E)
              Piston ring ISO 6626-3 SOR-S - 100 × 3 × 0,20 – MC65/NT030 WF CSE PN1,5
4.2 Type SOV — Steel oil control rings with V-shaped groove
4.2.1 General features and dimensions
Figure 2 shows the general features and dimensions of piston ring type SOV.
Dimensions in millimetres
Deleted:
NOTE 1 For definitions of symbols, see
Clause 3.¶
Key
NOTE 2 For dimensions, see Tables 3,
4, 5, 12, 18, 19 and 20.¶
1 reference plane
Formatted: Font:
NOTE 1 For definitions of symbols, see Clause 3.
NOTE 2 For dimensions, see Tables 1, 2, 3, 4, 5, 11, 13, 14, 20, 21 and 22. Formatted: Font:
Figure 2 — General features and dimensions of piston ring type SOV
4.2.2 Designation
EXAMPLE A coil‐spring‐loaded oil control ring with V‐shaped groove (SOV), a radial wall thickness
class = small (S), V‐shaped groove angle 40° (V40), of nominal diameter d = 100 mm (100), a nominal ring width
1
h = 3 mm (3), a land width h = 0,20 mm (0,20), made of steel MC65 (MC65), a nitrided depth of 0,030 mm min.
1 5
(NT030), coil spring with reduced heat set (WF), and constant pitch with coil diameter d ground (CSN), medium
7
nominal contact pressure p = 1,5 MPa (PN1,5):
0
              Piston ring ISO 6626-3 SOV-S-V40 - 100 × 3 × 0,20 – MC65/NT030 WF CSN PN1,5
5 Common features
5.1 Ring width h and radial wall thickness a
1 1
Table 1 shows common features for ring width h and radial wall thickness a.
1 1
Table 1 — Ring width h and radial wall thickness a
1 1
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ISO 6626-3:2016(E)
Dimensions in millimetres
Radial wall thickness
Ring width
a 0,15
1

Type
0,01
h 
10,03
Small Large
(Code: S) (Code: L)
1,5 1,5 to 1,8 — SOR
2,0 1,8 to 2,0 — SOR
2,5 1,8 to 2,0 — SOR
3,0 1,8 to 2,0 2,3 to 2,6 SOR and SOV
4,0 2,0 to 2,6 2,8 to 3,2 SOR and SOV
5.2 Land width h
5
Table 2 shows common features for land width h.
5
Table 2 — Land width h
5
Dimensions in millimetres
Land width
Ring width
h 0,07
h1
5
1,5 0,18 — —
2,0 0,20 — —
2,5 0,20 0,25 —
3,0 0,20 0,25 0,30
a
4,0 0,20 0,25 0,30
a
For diameters greater than 120 mm and ring width equal to
4,0 mm, land width equal to 0,20 mm shall not be used.
5.3 Land angle α, β
Table 3 shows common features for land angle α, β.
Table 3 — Land angle α, β
Range of
Land angle Tolerance
nominal angle
a
inside α 5° to 20° ±5°
a
outside β 10° to 30° ±5°
a
Nominal angle subject to agreement between
manufacturer and customer.
5.4 Land spacing B
3
Table 4 shows common features for land spacing B3.
Table 4 — Land spacing B
3
Dimensions in millimetres
Ring width Land spacing
h B
1 3
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ISO 6626-3:2016 (E)
1,5 0,90 to 1,00
a
2,0 1,25 to 1,45
a
2,5 1,35 to 1,75
a
3,0 1,45 to 2,10
a
4,0 1,80 to 3,20
a
B > (c + 0,95).
3 1
5.5 Slot sizes
Table 5 shows common features for slot sizes.
Table 5 — Standard slot sizes
Dimensions in millimetres
Ring width Slot width Slot length Slot spacing
h c w w
1 1 1 3
1,5 0,3 to 0,5 1,4 to 2,5 5 to 10
2,0 0,3 to 0,5 1,4 to 2,5 5 to 10
2,5 0,4 to 0,6 2,0 to 3,0 5 to 10
3,0 0,5 to 0,7 2,5 to 3,5 5 to 10
4,0 0,6 to 1,0 3,0 to 5,0 5 to 10
Slots may open into the gap faces (see Figure 3).

Figure 3 — Arrangement of slots
5.6 Nitrided surface
Table 6 shows common features for nitrided surfaces.
Table 6 — Nitrided case depth of peripheral surface and sideface
Dimensions in millimetres
a
Nitrided case depth
Code Peripheral surface Sideface
min. min.
NT010 0,010 0,005
NT030 0,030 0,010
b
NT050 0,050 0,015
a
Deleted: Not
It is not recommended for rings h1 = 1,5 mm.
b
It is not recommended for land width h5 ≤ 0,20 mm.
Deleted: Not
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ISO 6626-3:2016(E)
5.7 PVD coating thickness of peripheral surface
Table 7 shows PVD coating thickness of peripheral surface.
Table 7 — PVD coating thickness of peripheral surface
Dimensions in millimetres
PVD coating thickness
Code Peripheral surface
min.
PC001 0,001
PC003 0,003
PC005 0,005
a
PC010 0,010
a
PC020 0,020
a
Not typical for diamond‐like carbon (DLC) coatings.
5.8 Nominal contact pressure and tangential force
5.8.1 Nominal contact pressure
Table 8 shows common features for nominal contact pressure.
Table 8 — Nominal contact pressure classes

Nominal contact pressure
p
0
Ring width MPa
h Code Code Code Code
1
mm PN1,0 PN1,5 PN2,0 PN2,5
1,5 1,0 1,5 — —
2,0 1,0 1,5 2,0 —
2,5 1,0 1,5 2,0 —
3,0 — 1,5 2,0 2,5
4,0 — 1,5 2,0 2,5
5.8.2 Actual tangential force, F , and tolerance
t
The actual tangential force of a spring‐loaded oil control ring can be calculated with the tabulated
normalized tangential force, F/d, given in Table 7, according to the required nominal contact pressure,
t 1
p, from the equation:
0
FF d
tN1
The tolerance on F is the actual value F ± 20 %. Actual values of tangential force should be rounded up
t t
or down in accordance with ISO 6621‐4.
5.8.3 Normalized tangential force, FN
The normalized tangential force FN is defined:
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ISO 6626-3:2016 (E)
F
t
F 

N
d
1
For different nominal contact pressure, p, F is tabulated in Table 9.
0 N
Table 9 — Normalized tangential forces, F
N
h5
Code 0,18 0,2 0,25 0,28 0,30 0,35 0,40 0,50 0,60 0,70 0,80 0,90 1,10 1,30 1,60
p
0
PN2,5 2,5 0,45 0,50 0,63 0,70 0,75 0,88 1,00 1,25 1,50 1,75 2,00 2,25 2,75 3,25 4,00
PN2,0 2,0 0,36 0,40 0,50 0,56 0,60 0,70 0,80 1,00 1,20 1,40 1,60 1,80 2,20 2,60 3,20
PN1,5 1,5 0,27 0,30 0,38 0,42 0,45 0,53 0,60 0,75 0,90 1,05 1,20 1,35 1,65 1,95 2,40
PN1,0 1,0 0,18 0,20 0,25 0,28 0,30 0,35 0,40 0,50 0,60 0,70 0,80 0,90 1,10 1,30 1,60
0,09
PN0,5 0,5 0,10 0,13 0,14 0,15 0,18 0,20 0,25 0,30 0,35 0,40 0,45 0,55 0,65 0,80
5.9 Tolerance of tangential force F
t
Table 10 shows common features for tangential force Ft, following Formula (1):
Fdhp (1)
t1 5 0
Table 10 — Tolerance of tangential force Ft
Tangential force
Tolerance
N
F < 20 ±4 N
t
F ≥ 20 ±20 %
t
6 Coil springs
6.1 Types of coil spring
6.1.1 All values in the dimensional tables are based on cylindrical coil springs made of round wire.
The three designs shown in Figures 4 to 7 are common.
6.1.2 Figure 4 illustrates the design of type CSN coil spring with constant pitch.

Figure 4 — Type CSN coil spring
6.1.3 Figure 5 illustrates the design of type CSG coil spring with constant pitch (coil diameter d
7
ground).
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ISO 6626-3:2016(E)

Key
1 approx. 0,8 × d8 ‐ diameter of wire
Figure 5 — Type CSG coil spring
6.1.4 Figure 6 illustrates the design of type CSE coil spring with variable pitch (coil diameter d
7
ground), and Figure 7 shows the position of the area with small pitch.

Key
1 approx. 0,8 × d8 ‐ diameter of wire
Figure 6 — Type CSE coil spring
Dimensions in millimetres
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ISO 6626-3:2016 (E)

Key
1 spring gap
2 area with small pitch
a
Latch pin free length.
b
Latch pin fixed length.
Figure 7 — Position of area with small pitch
NOTE The use of different spring designs can be agreed between manufacturer and customer. Changed
spring groove configurations and dimensions can then be necessary.
6.2 Coil-spring excursion (extended gap)
Coil‐spring excursion, f, is the distance between the ends of the ring gap, with unstressed ring,
1
measured in the middle of the spring groove (see Figure 8 and Table 11).

Figure 8 — Coil-spring excursion
Table 11 — Coil-spring excursion
Dimensions in millimetres
Coil-spring excursion
Nominal diameter
f
1
d
1
max.
60 ≤ d < 100 0,1 × d
1 1
100 ≤ d ≤ 160 0,12 × d
1 1
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ISO 6626-3:2016(E)
6.3 Position of coil spring gap and fixing
The spring gap shall be approximately 180° from the ring gap and the spring gap ends fixed with a
connecting or latch pin.
6.4 Material
Coil springs are made of materials as shown in ISO 6621‐3, subclasses MC62 (valve spring wire), MC67
(stainless steel) and MC68 (piano wire).
Springs are available with two different heat set resistance levels (loss of tangential force under load
and temperature):
— standard heat resistance;
— reduced heat set, code WF.
The test conditions and the permissible loss of tangential forces are given in ISO 6621‐5.
7 Type SOR
Table 12 gives the tolerance and calculation criteria on a, a , a , d , d and a for type SOR. Deleted: a14
4 13 17 14 7 12
Table 12 — Tolerance and calculation criteria on a , a , a , d , d and a for type SOR Deleted: a
4 13 17 14 7 12 14
Dimensions in millimetres
Item Symbol Tolerance Calculation criteria
Groove depth a ±0,1 a = (0,35 to 0,6) × a − 0,2
4 4 1
Groove depth and bridge a ±0,1 a = a4 + (0,45 to 0,65)
13 13
a
a
Deleted: a14
External land depth a max. a = (0,1 to 0,3) × a
17 17 1
Deleted: a14
b
Coil‐spring groove diameter d ±0,05 d = (0,65 to 0,85)
14 14
Coil‐spring diameter d ±0,05 d = d – (0,1 to 0,4)
7 7 14
Radial thickness over coil spring a12 ±0,15 a12 = a13 + d7
a
This value is to be determined between manufacturer and customer.
b
When h is 1,5 to 2,5, d = (0,75 to 0,85) × h.
1 14 1
8 Type SOV
8.1 The angle of inside groove, θ, is as follows:
40° ± 1° (code V40) or 45° ± 1° (code V45) ± 1° (angle to reference plane).
See Figure 2.
8.2 Table 13 gives the tolerance and calculation criteria on a, a , a , d and a for type SOV. Deleted: a14, d14
4 13 17 7 12
Table 13 — Tolerance and calculation criteria on a , a , a , d and a for type SOV Deleted: a14, d14
4 13 17 7 12
Dimensions in millimetres
Item Symbol Tolerance Calculation criteria
a
Groove depth ±0,1 aa0,35to0,60,3
4 41

a aa 0,45to0,65
Groove depth and bridge ±0,1  
13 13 4

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ISO 6626-3:2016 (E)
a
a Deleted: a
a
External land depth max. aa0,1to0,3 14
17 17 1
d
dh0,6to0,8
Coil‐spring diameter ±0,05
7 71
d
1
7
a aa0,1to0,4 1 
Radial thickness over coil spring ±0,15 
12 12 4 
sin 2


a
This value is to be determined between manufacturer and customer.
9 Dimensions
The two cross‐sections specified in this document (SOR and SOV) are applicable for different diameter
ranges. Table 14 provides a summary of the specifications given in Tables 15 to 22. The detailed
Tables 15 to 22 contain the recommended nominal tangential forces of all types and diameters shown
in Table 14.
Table 14 — Index of Tables 15 to 22
Dimensions in millimetres
Ring width Radial wall thickness Nominal diameter
Table Type
h a d
1 1 1
15 1,5 SOR‐S 60 to 89
16 2,0 and 2,5 SOR‐S 60 to 100
17 SOR 3,0 SOR‐S and SOR‐L 65 to 120
18 4,0 SOR‐S and SOR‐L 80 to 124
19 4,0 SOR‐S and SOR‐L 125 to 160
20 3,0 SOV‐S and SOV‐L 70 to 120
21 SOV 4,0 SOV‐S and SO
...

INTERNATIONAL ISO
STANDARD 6626-3
Second edition
2019-09
Internal combustion engines —
Piston rings —
Part 3:
Coil-spring-loaded oil control rings
made of steel
Moteurs à combustion interne — Segments de piston —
Partie 3: Segments racleurs régulateurs d'huile, en acier, mis en
charge par ressort hélicoïdal
Reference number
ISO 6626-3:2019(E)
©
ISO 2019

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ISO 6626-3:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
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
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Phone: [phone]
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Published in Switzerland
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ISO 6626-3:2019(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Symbols . 1
4 Piston ring types and designation examples . 2
4.1 Type SOR — Steel oil control rings with R-shaped groove . 2
4.1.1 General features and dimensions . 2
4.1.2 Designation . 3
4.2 Type SOV — Steel oil control rings with V-shaped groove. 3
4.2.1 General features and dimensions . 3
4.2.2 Designation . 4
5 Common features . 4
5.1 Ring width h and radial wall thickness a . 4
1 1
5.2 Land width h . 5
5
5.3 Land angle α, β . 5
5.4 Land spacing B . 5
3
5.5 Slot sizes . 6
5.6 Nitrided surface. 6
5.7 PVD coating thickness of peripheral surface . 7
5.8 Nominal contact pressure and tangential force . 7
5.8.1 Nominal contact pressure . 7
5.8.2 Actual tangential force, F , and tolerance . 8
t
5.8.3 Normalized tangential force, F .
N 8
5.9 Tolerance of tangential force F . 8
t
6 Coil springs . 8
6.1 Types of coil spring . 8
6.2 Coil-spring excursion (extended gap) .10
6.3 Position of coil spring gap and fixing .11
6.4 Material .11
7 Type SOR .11
8 Type SOV .11
9 Dimensions .12
Bibliography .26
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ISO 6626-3:2019(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.
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).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
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 22, Road vehicles, Subcommittee SC 34,
Propulsion, powertrain and powertrain fluids.
This second edition cancels and replaces the first edition (ISO 6266-3:2008), which has been technically
revised. The main changes compared to the previous edition are as follows:
— added subclause 5.8.2, Actual tangential force, F and tolerance;
t
— added subclause 5.8.3, Normalized tangential force, F ;
N
— added Table 9, Normalized tangential forces, F ;
N
— raised table numbers by one from Table 9 onward;
— made editorial changes to Table 16.
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.
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ISO 6626-3:2019(E)

Introduction
ISO 6626 (all parts) is one of a series of International Standards dealing with piston rings for
reciprocating internal combustion engines. Others are ISO 6621 (all parts), ISO 6622 (all parts),
ISO 6623, ISO 6624 (all parts), ISO 6625 and ISO 6627 (see Clause 2 and Bibliography).
The common features and dimensional tables presented in this document constitute a broad range of
variables and, in selecting a particular ring type, the designer will bear in mind the conditions under
which it will be required to operate.
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INTERNATIONAL STANDARD ISO 6626-3:2019(E)
Internal combustion engines — Piston rings —
Part 3:
Coil-spring-loaded oil control rings made of steel
1 Scope
This document specifies the essential dimensions of coil-spring-loaded oil control rings made of steel,
of piston ring types SOR (with R-shaped groove) and SOV (with V-shaped groove).
This document applies to coil-spring-loaded oil control rings made of steel with a diameter from 60 mm
up to and including 160 mm for reciprocating internal combustion engines. It can also be used for piston
rings in compressors working under analogous conditions.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and symbols
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1 Symbols
a radial wall thickness
1
a groove depth
4
a radial thickness over coil spring
12
a groove depth and bridge
13
a external land depth
17
B land spacing
3
c slot width
1
d nominal diameter (nominal bore diameter)
1
d coil-spring diameter
7
d coil-spring groove diameter for type SOR
14
f coil-spring excursion
1
F tangential force
t
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ISO 6626-3:2019(E)

h ring width
1
h land width
5
p contact pressure
0
s closed gap
1
w slot length
1
w slot spacing
3
α land angle inside
β land angle outside
θ groove angle for type SOV
NOTE These symbols (including associated indices) are in accordance with the symbols used in
ISO 6621 (all parts), ISO 6622 (all parts), ISO 6623, ISO 6624 (all parts), ISO 6625, ISO 6627 and other parts of the
ISO 6626 series.
4 Piston ring types and designation examples
4.1 Type SOR — Steel oil control rings with R-shaped groove
4.1.1 General features and dimensions
Figure 1 shows the general features and dimensions of piston ring type SOR.
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ISO 6626-3:2019(E)

Dimensions in millimetres
Key
1 reference plane
NOTE 1  For definitions of symbols, see Clause 3.
NOTE 2  For dimensions, see Tables 1, 2, 3, 4, 5, 11, 12, 14, 15, 16, 17, 18 and 19.
Figure 1 — General features and dimensions of piston ring type SOR
4.1.2 Designation
EXAMPLE A coil-spring-loaded oil control ring with R-shaped groove (SOR), a radial wall thickness
class = small (S), of nominal diameter d = 100 mm (100), a nominal ring width h = 3 mm (3), a land width
1 1
h = 0,20 mm (0,20), made of steel MC65 (MC65), a nitrided depth of 0,030 mm min. (NT030), coil spring with
5
reduced heat set (WF), and variable pitch with coil diameter d ground (CSE), medium nominal contact pressure
7
p = 1,5 MPa (PN1,5):
0
              Piston ring ISO 6626-3 SOR-S - 100 × 3 × 0,20 – MC65/NT030 WF CSE PN1,5
4.2 Type SOV — Steel oil control rings with V-shaped groove
4.2.1 General features and dimensions
Figure 2 shows the general features and dimensions of piston ring type SOV.
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ISO 6626-3:2019(E)

Dimensions in millimetres
Key
1 reference plane
NOTE 1  For definitions of symbols, see Clause 3.
NOTE 2  For dimensions, see Tables 1, 2, 3, 4, 5, 11, 13, 14, 20, 21 and 22.
Figure 2 — General features and dimensions of piston ring type SOV
4.2.2 Designation
EXAMPLE A coil-spring-loaded oil control ring with V-shaped groove (SOV), a radial wall thickness
class = small (S), V-shaped groove angle 40° (V40), of nominal diameter d = 100 mm (100), a nominal ring width
1
h = 3 mm (3), a land width h = 0,20 mm (0,20), made of steel MC65 (MC65), a nitrided depth of 0,030 mm min.
1 5
(NT030), coil spring with reduced heat set (WF), and constant pitch with coil diameter d ground (CSN), medium
7
nominal contact pressure p = 1,5 MPa (PN1,5):
0
Piston ring ISO 6626-3 SOV-S-V40 - 100 × 3 × 0,20 – MC65/NT030 WF CSN PN1,5
5 Common features
5.1 Ring width h and radial wall thickness a
1 1
Table 1 shows common features for ring width h and radial wall thickness a .
1 1
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ISO 6626-3:2019(E)

Table 1 — Ring width h and radial wall thickness a
1 1
Dimensions in millimetres
Radial wall thickness
Ring width
a ±01, 5
1 Type
−00, 1
h =
10− ,03 Small Large
(Code: S) (Code: L)
1,5 1,5 to 1,8 — SOR
2,0 1,8 to 2,0 — SOR
2,5 1,8 to 2,0 — SOR
3,0 1,8 to 2,0 2,3 to 2,6 SOR and SOV
4,0 2,0 to 2,6 2,8 to 3,2 SOR and SOV
5.2 Land width h
5
Table 2 shows common features for land width h .
5
Table 2 — Land width h
5
Dimensions in millimetres
Land width
Ring width
h
h ± 00, 7
1
5
1,5 0,18 — —
2,0 0,20 — —
2,5 0,20 0,25 —
3,0 0,20 0,25 0,30
a
4,0 0,20 0,25 0,30
a
For diameters greater than 120 mm and ring width equal
to 4,0 mm, land width equal to 0,20 mm shall not be used.
5.3 Land angle α, β
Table 3 shows common features for land angle α, β.
Table 3 — Land angle α, β
Range of
Land angle Tolerance
nominal angle
a
inside α 5° to 20° ±5°
a
outside β 10° to 30° ±5°
a
Nominal angle subject to agreement between
manufacturer and customer.
5.4 Land spacing B
3
Table 4 shows common features for land spacing B .
3
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ISO 6626-3:2019(E)

Table 4 — Land spacing B
3
Dimensions in millimetres
Ring width Land spacing
h B
1 3
1,5 0,90 to 1,00
a
2,0 1,25 to 1,45
a
2,5 1,35 to 1,75
a
3,0 1,45 to 2,10
a
4,0 1,80 to 3,20
a
B > (c + 0,95).
3 1
5.5 Slot sizes
Table 5 shows common features for slot sizes.
Table 5 — Standard slot sizes
Dimensions in millimetres
Ring width Slot width Slot length Slot spacing
h c w w
1 1 1 3
1,5 0,3 to 0,5 1,4 to 2,5 5 to 10
2,0 0,3 to 0,5 1,4 to 2,5 5 to 10
2,5 0,4 to 0,6 2,0 to 3,0 5 to 10
3,0 0,5 to 0,7 2,5 to 3,5 5 to 10
4,0 0,6 to 1,0 3,0 to 5,0 5 to 10
Slots may open into the gap faces (see Figure 3).
Figure 3 — Arrangement of slots
5.6 Nitrided surface
Table 6 shows common features for nitrided surfaces.
Table 6 — Nitrided case depth of peripheral surface and sideface
Dimensions in millimetres
a
Nitrided case depth
Code Peripheral surface Sideface
min. min.
NT010 0,010 0,005
a
It is not recommended for rings h = 1,5 mm.
1
b
It is not recommended for land width h ≤ 0,20 mm.
5
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ISO 6626-3:2019(E)

Table 6 (continued)
a
Nitrided case depth
Code Peripheral surface Sideface
min. min.
NT030 0,030 0,010
b
NT050 0,050 0,015
a
It is not recommended for rings h = 1,5 mm.
1
b
It is not recommended for land width h ≤ 0,20 mm.
5
5.7 PVD coating thickness of peripheral surface
Table 7 shows PVD coating thickness of peripheral surface.
Table 7 — PVD coating thickness of peripheral surface
Dimensions in millimetres
PVD coating thickness
Code Peripheral surface
min.
PC001 0,001
PC003 0,003
PC005 0,005
a
PC010 0,010
a
PC020 0,020
a
Not typical for diamond-like carbon (DLC) coatings.
5.8 Nominal contact pressure and tangential force
5.8.1 Nominal contact pressure
Table 8 shows common features for nominal contact pressure.
Table 8 — Nominal contact pressure classes
Nominal contact pressure
p
0
Ring width MPa
h Code Code Code Code
1
mm PN1,0 PN1,5 PN2,0 PN2,5
1,5 1,0 1,5 — —
2,0 1,0 1,5 2,0 —
2,5 1,0 1,5 2,0 —
3,0 — 1,5 2,0 2,5
4,0 — 1,5 2,0 2,5
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ISO 6626-3:2019(E)

5.8.2 Actual tangential force, F , and tolerance
t
The actual tangential force of a spring-loaded oil control ring can be calculated with the tabulated
normalized tangential force, F /d , given in Table 7, according to the required nominal contact pressure,
t 1
p , from the equation:
0
FF=⋅d
tN 1
The tolerance on F is the actual value F ± 20 %. Actual values of tangential force should be rounded up
t t
or down in accordance with ISO 6621-4.
5.8.3 Normalized tangential force, F
N
The normalized tangential force F is defined:
N
 F 
t
F =
 
N
d
1
 
For different nominal contact pressure, p , F is tabulated in Table 9.
0 N
Table 9 — Normalized tangential forces, F
N
h
5
Code 0,18 0,2 0,25 0,28 0,30 0,35 0,40 0,50 0,60 0,70 0,80 0,90 1,10 1,30 1,60
p
0
PN2,5 2,5 0,45 0,50 0,63 0,70 0,75 0,88 1,00 1,25 1,50 1,75 2,00 2,25 2,75 3,25 4,00
PN2,0 2,0 0,36 0,40 0,50 0,56 0,60 0,70 0,80 1,00 1,20 1,40 1,60 1,80 2,20 2,60 3,20
PN1,5 1,5 0,27 0,30 0,38 0,42 0,45 0,53 0,60 0,75 0,90 1,05 1,20 1,35 1,65 1,95 2,40
PN1,0 1,0 0,18 0,20 0,25 0,28 0,30 0,35 0,40 0,50 0,60 0,70 0,80 0,90 1,10 1,30 1,60
PN0,5 0,5 0,09 0,10 0,13 0,14 0,15 0,18 0,20 0,25 0,30 0,35 0,40 0,45 0,55 0,65 0,80
5.9 Tolerance of tangential force F
t
Table 10 shows common features for tangential force F , following Formula (1):
t
Fd=×hp× (1)
t 15 0
Table 10 — Tolerance of tangential force F
t
Tangential force
Tolerance
N
F < 20 ±4 N
t
F ≥ 20 ±20 %
t
6 Coil springs
6.1 Types of coil spring
6.1.1 All values in the dimensional tables are based on cylindrical coil springs made of round wire.
The three designs shown in Figures 4 to 7 are common.
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ISO 6626-3:2019(E)

6.1.2 Figure 4 illustrates the design of type CSN coil spring with constant pitch.
Figure 4 — Type CSN coil spring
6.1.3 Figure 5 illustrates the design of type CSG coil spring with constant pitch (coil diameter d
7
ground).
Key
1 approx. 0,8 × d - diameter of wire
8
Figure 5 — Type CSG coil spring
6.1.4 Figure 6 illustrates the design of type CSE coil spring with variable pitch (coil diameter d
7
ground), and Figure 7 shows the position of the area with small pitch.
Key
1 approx. 0,8 × d - diameter of wire
8
Figure 6 — Type CSE coil spring
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ISO 6626-3:2019(E)

Dimensions in millimetres
Key
1 spring gap
2 area with small pitch
a
Latch pin free length.
b
Latch pin fixed length.
Figure 7 — Position of area with small pitch
NOTE The use of different spring designs can be agreed between manufacturer and customer. Changed
spring groove configurations and dimensions can then be necessary.
6.2 Coil-spring excursion (extended gap)
Coil-spring excursion, f , is the distance between the ends of the ring gap, with unstressed ring,
1
measured in the middle of the spring groove (see Figure 8 and Table 11).
Figure 8 — Coil-spring excursion
Table 11 — Coil-spring excursion
Dimensions in millimetres
Coil-spring excursion
Nominal diameter
f
1
d
1
max.
60 ≤ d < 100 0,1 × d
1 1
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ISO 6626-3:2019(E)

Table 11 (continued)
Coil-spring excursion
Nominal diameter
f
1
d
1
max.
100 ≤ d ≤ 160 0,12 × d
1 1
6.3 Position of coil spring gap and fixing
The spring gap shall be approximately 180° from the ring gap and the spring gap ends fixed with a
connecting or latch pin.
6.4 Material
Coil springs are made of materials as shown in ISO 6621-3, subclasses MC62 (valve spring wire), MC67
(stainless steel) and MC68 (piano wire).
Springs are available with two different heat set resistance levels (loss of tangential force under load
and temperature):
— standard heat resistance;
— reduced heat set, code WF.
The test conditions and the permissible loss of tangential forces are given in ISO 6621-5.
7 Type SOR
Table 12 gives the tolerance and calculation criteria on a , a , a , d , d and a for type SOR.
4 13 17 14 7 12
Table 12 — Tolerance and calculation criteria on a , a , a , d , d and a for type SOR
4 13 17 14 7 12
Dimensions in millimetres
Item Symbol Tolerance Calculation criteria
Groove depth a ±0,1 a = (0,35 to 0,6) × a − 0,2
4 4 1
Groove depth and bridge a ±0,1 a = a4 + (0,45 to 0,65)
13 13
a
External land depth a max. a = (0,1 to 0,3) × a
17 17 1
b
Coil-spring groove diameter d ±0,05 d = (0,65 to 0,85)
14 14
Coil-spring diameter d ±0,05 d = d – (0,1 to 0,4)
7 7 14
Radial thickness over coil spring a ±0,15 a = a + d
12 12 13 7
a
This value is to be determined between manufacturer and customer.
b
When h is 1,5 to 2,5, d = (0,75 to 0,85) × h .
1 14 1
8 Type SOV
8.1 The angle of inside groove, θ, is as follows:
40° ± 1° (code V40) or 45° ± 1° (code V45) ± 1° (angle to reference plane).
See Figure 2.
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ISO 6626-3:2019(E)

8.2 Table 13 gives the tolerance and calculation criteria on a , a , a , d and a for type SOV.
4 13 17 7 12
Table 13 — Tolerance and calculation criteria on a , a , a , d and a for type SOV
4 13 17 7 12
Dimensions in millimetres
Item Symbol Tolerance Calculation criteria
Groove depth a ±0,1
4 aa=×03,,50 to 60− ,3
()
41
Groove depth and bridge a ±0,1
13
aa=+ ()04,,50 to 65
13 4
a
External land depth a max.
17
aa=×01,, to03
()
17 1
Coil-spring diameter d ±0,05
7 dh=×()06,, to08
71
1 d
 
7
Radial thickness over coil spring a ±0,15
12 aa=+ −+01,, to04 1 +×
()
12 4  
sinθ 2
 
a
This value is to be determined between manufacturer and customer.
9 Dimensions
The two cross-sections specified in this document (SOR and SOV) are applicable for different diameter
ranges. Table 14 provides a summary of the specifications given in Tables 15 to 22. The detailed
Tables 15 to 22 contain the recommended nominal tangential forces of all types and diameters shown
in Table 14.
Table 14 — Index of Tables 15 to 22
Dimensions in millimetres
Ring width Radial wall thickness Nominal diameter
Table Type
h a d
1 1 1
15 1,5 SOR-S 60 to 89
16 2,0 and 2,5 SOR-S 60 to 100
17 SOR 3,0 SOR-S and SOR-L 65 to 120
18 4,0 SOR-S and SOR-L 80 to 124
19 4,0 SOR-S and SOR-L 125 to 160
20 3,0 SOV-S and SOV-L 70 to 120
21 SOV 4,0 SOV-S and SOV-L 80 to 124
22 4,0 SOV-S and SOV-L 125 to 160
NOTE  Codes S and L are described in Table 1.
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ISO 6626-3:2019(E)

Table 15 — Recommended nominal tangential force of ring type SOR-S (h = 1,5 mm)
1
Recommended nominal
tangential force
N
Ring type SOR-S
Nominal Closed
diameter gap
−00, 1
h =15,
1 −00, 3
d s
1 1
mm mm
h = 0,18 ± 0,07
5
PN1,0 PN1,5
(1,0 MPa) (1,5 MPa)
60 10,8 16,2
61 11 16,5
62 11,2 16,7
63 11,3 17
64 11,5 17,3
65 11,7 17,6
66 11,9 17,8
67 12,1 18,1
+02,
02,
  0
68 12,2
69 12,4
70 12,6
71 12,8
72 13,0
73 13,1
74 13,3
75 13,5
76 13,7
77 13,9
78 14 —
79 14,2
80 14,4
81 14,6
+02,
02, 5
82  0 14,8
83 14,9
84 15,1
85 15,3
86 15,5
87 15,7
88 15,8
89 16
Diameters without value for tangential force are not recommended
for use.
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ISO 6626-3:2019(E)

Table 16 — Recommended nominal tangential force of ring type SOR-S (h = 2,0 mm and
1
h = 2,5 mm)
1
Recommended nominal tangential force
N
Ring type SOR-S
Nominal Closed mm
diameter gap
−00, 1 −00, 1
d s
1 1 h =20, h =25,
10− ,03 10− ,03
mm mm
h = 0,2 ± 0,07 h = 0,2 ± 0,07 h = 0,25 ± 0,07
5 5 5
PN1,0 PN1,5 PN2,0 PN1,0 PN1,5 PN2,0 PN1,0 PN1,5 PN2,0
(1,0 MPa) (1,5 MPa) (2,0 MPa) (1,0 MPa) (1,5 MPa) (2,0 MPa) (1,0 MPa) (1,5 MPa) (2,0 MPa)
60 12 18 24 12 18 24 15 22,5 30
61 12,2 18,3 24,4 12,2 18,3 24,4 15,3 22,9 30,5
62 12,4 18,6 24,8 12,4 18,6 24,8 15,5 23,3 31
63 12,6 18,9 25,2 12,6 18,9 25,2 15,8 23,7 31,5
64 12,8 19,2 25,6 12,8 19,2 25,6 16 24 32
65 13 19,5 26 13 19,5 26 16,3 24,4 32,5
66 13,2 19,8 13,2 19,8 26,4 16,5 24,8 33
67 13,4 20,1 13,4 20,1 26,8 16,8 25,1 33,5
+02,
02,
68 13,6 20,4 13,6 20,4 27,2 17 25,5 34
  0
69 13,8 20,7 13,8 20,7 27,6 17,3 25,9 34,5
70 14 21 — 14 21 28 17,5 26,3 35
71 14,2 21,3 14,2 21,3 28,4 17,8 26,6 35,5
72 14,4 21,6 14,4 21,6 28,8 18 27 36
73 14,6 21,9 14,6 21,9 29,2 18,3 27,4 36,5
74 14,8 22,2 14,8 22,2 29,6 18,5 27,8 37
75 15 22,5 15 22,5 30 18,8 28,1 37,5
76 15,2 22,8 15,2 22,8 30,4 19 28,5 38
77 15,4 23,1 15,4 23,1 30,8 19,3 28,9 38,5
78 15,6 23,4 15,6 23,4 31,2 19,5 29,3 39
79 15,8 23,7 15,8 23,7 31,6 19,8 29,6 39,5
80 16 24 16 24 32 20 30 40
81 16,2 24,3 16,2 24,3 32,4 20,3 30,4 40,5
+02,
02, 5
82 16,4 24,6 — 16,4 24,6 32,8 20,5 30,8 41
  0
83 16,6 24,9 16,6 24,9 33,2 20,8 31,1 41,5
84 16,8 25,2 16,8 25,2 33,6 21 31,5 42
85 17 25,5 17 25,5 34 21,3 31,9 42,5
86 17,2 25,8 17,2 25,8 34,4 21,5 32,3
87 17,4 26,1 17,4 26,1 34,8 21,8 32,6 —
88 17,6 26,4 17,6 26,4 35,2 22 33
89 17,8 26,7 17,8 26,7 35,6 22,3 33,4
90 18 27 18 27 36 22,5 33,8
91 18,2 18,2 27,3 36,4 22,8 34,1
92 18,4 18,4 27,6 36,8 23 34,5
+02, 5
03,
93 18,6 18,6 27,9 37,2 23,3 34,9
  0
94 18,8 18,8 28,2 37,6 23,5 35,3
95 19 19 28,5 38 23,8 35,6
96 19,2 28,8 38,4 24 36
97 19,4 29,1 38,8 24,3 36,4
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ISO 6626-3:2019(E)

Table 16 (continued)
Recommended nominal tangential force
N
Ring type SOR-S
Nominal Closed mm
diameter gap
−00, 1 −00, 1
d s
1 1 h =20, h =25,
10− ,03 10− ,03
mm mm
h = 0,2 ± 0,07 h = 0,2 ± 0,07 h = 0,25 ± 0,07
5 5 5
PN1,0 PN1,5 PN2,0 PN1,0 PN1,5 PN2,0 PN1,0 PN1,5 PN2,0
(1,0 MPa) (1,5 MPa) (2,0 MPa) (1,0 MPa) (1,5 MPa) (2,0 MPa) (1,0 MPa) (1,5 MPa) (2,0 MPa)
98 19,6 29,4 39,2 24,5 36,8
99 — 19,8 29,7 39,6 24,8 37,1 —
+02, 5
03,
100 — 20 30 40 25 37,5
  0
101
102 —
103
104
105 — — — — —
106
107
108
109
110
111
112
113
114
115
116
+02, 5
03, 5
117 — — — — — — — — —
  0
118
119
120
121
122
123
124
Diameters without value for tangential force are not recommended for use.
© ISO 2019 – All rights reserved 15

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ISO 6626-3:2019(E)

Table 17 — Recommended nominal tangential force of ring type SOR-S and SOR-L (h = 3,0 mm)
1
Recommended nominal tangential force
N
Ring type SOR-S Ring type SOR-L
mm mm
Nominal Closed
diameter gap
−00, 1 −00, 1
d s
1 1 h =30, h =30,
10− ,03 10− ,03
mm mm
h = 0,2 ± 0,07 h = 0,25 ± 0,07 h = 0,2 ± 0,07 h = 0,25 ± 0,07
5 5 5 5
PN2,0
PN1,5 PN2,5 PN1,5 PN2,0 PN2,5 PN1,5 PN2,0 PN2,5 PN1,5 PN2,0 PN2,5
(2,0
(1,5 MPa) (2,5 MPa) (1,5 MPa) (2,0 MPa) (2,5 MPa) (1,5 MPa) (2,0 MPa) (2,5 MPa) (1,5 MPa) (2,0 MPa) (2,5MPa)
MPa)
60
61
62 — — — — — —
63
64
65 19,5
...