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SIST ISO 68-2:2002
01-februar-2002
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ISO general-purpose screw threads -- Basic profile -- Part 2: Inch screw threads
Filetages ISO pour usages généraux -- Profil de base -- Partie 2: Filetages en inches
Ta slovenski standard je istoveten z: ISO 68-2:1998
ICS:
21.040.20 Colski navoji Inch screw threads
SIST ISO 68-2:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST ISO 68-2:2002
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SIST ISO 68-2:2002
INTERNATIONAL ISO
STANDARD 68-2
First edition
1998-12-15
ISO general purpose screw threads —
Basic profile —
Part 2:
Inch screw threads
Filetages ISO pour usages généraux — Profil de base —
Partie 2: Filetages en inches
A
Reference number
ISO 68-2:1998(E)
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SIST ISO 68-2:2002
ISO 68-2:1998(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.
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.
International Standard ISO 68-2 was prepared by Technical Committee ISO/TC 1, Screw threads, Subcommittee
SC 1, Basic data.
This first edition, together with ISO 68-1, cancels and replaces ISO 68:1973 which has been technically revised by
separating the metric dimensions from the imperial dimensions.
ISO 68 consists of the following parts under the general title ISO general purpose screw threads – Basic profile
— Part 1: Metric screw threads
— Part 2: Inch screw threads
Annex of this part of ISO 68 is for information only.
© ISO 1998
or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet [email protected]
Printed in Switzerland
ii
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SIST ISO 68-2:2002
©
INTERNATIONAL STANDARD ISO ISO 68-2:1998(E)
ISO general purpose screw threads — Basic profile —
Part 2:
Inch screw threads
1 Scope
This part of ISO 68 specifies the basic profile for ISO inch screw threads.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this part of
ISO 68. At the time of publication the editions indicated were valid. All standards are subject to revision and parties
to agreements based on this part of ISO 68 are encouraged to investigate the possibility of applying the most recent
editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International
Standards.
ISO 5408:1983, Cylindrical screw threads – Vocabulary.
ISO 5864:1993, ISO inch screw threads — Allowances and tolerances.
3 Definitions
For the purpose of this part of ISO 68 the definitions given in ISO 5408 apply. Only the term "basic profile" which might be
usefully restated is defined below.
3.1
basic profile
The theoretical profile of a screw thread in an axial plane defined by theoretical dimensions and angles common to
internal and external threads
NOTE The basic profile is shown as a thick line in figure 1.
1
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SIST ISO 68-2:2002
©
ISO
ISO 68-2:1998(E)
where
D is the basic major diameter of internal thread (nominal diameter)
d is the basic major diameter of external thread (nominal diameter)
D
is the basic pitch diameter of internal thread
2
d is the basic pitch diameter of external thread
2
D
is the basic minor diameter of internal thread
1
d is the basic minor diameter of external thread
1
H is the height of fundamental triangle
P
is the pitch
Figure 1
4 Dimensions
The fundamental deviations and tolerances specified in ISO 5864 are applied to the dimensions of the basic profile
shown in figure 1 and derived from table 1.
0,866 025 404
H =
n
0,541 265 877
5
H =
8 n
3 0,324 759 526
H =
8 n
H 0,216 506 351
=
4 n
H 0,108 253 175
=
8 n
where n is the numbe
...