General tolerances

This part is intended to simplify drawing indications and specifies general tolerances in three tolerance classes. It mainly applies to features which are produced by removal of material. It contains tour tables and an informative annex A with regard to concepts behind general tolerancing of dimensions, as well as an informative annex B with further information.

Tolérances générales

La présente partie de l'ISO 2768 vise à simplifier les indications devant figurer sur les dessins et prescrit les tolérances géométriques générales applicables aux éléments du dessin qui ne font pas l'objet d'un tolérancement individuel. Elle prescrit des tolérances géométriques générales regroupées en trois classes de tolérance. La présente partie de l'ISO 2768 est applicable principalement aux éléments exécutés par enlèvement de matière. Son application à des éléments obtenus par d'autres procédés de fabrication est possible ; néanmoins, cela nécessite un contrôle supplémentaire pour déterminer si la précision habituelle de l'atelier demeure dans les limites des tolérances géométriques générales prescrites dans la présente partie de l'ISO 2768.

Splošne tolerance - 2. del: Tolerance geometrijskih značilnosti brez posebnih tolerančnih oznak

General Information

Status
Withdrawn
Publication Date
01-Nov-1989
Withdrawal Date
01-Nov-1989
Current Stage
9599 - Withdrawal of International Standard
Completion Date
02-Nov-1989

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.General tolerances -- Part 2: Geometrical tolerances for features without individual tolerance indicationsTolérances générales -- Partie 2: Tolérances géométriques pour éléments non affectés de tolérances individuelles17.040.10Tolerance in ujemiLimits and fitsICS:SIST ISO 2768-2:1999enTa slovenski standard je istoveten z:ISO 2768-2:198901-marec-1999SIST ISO 2768-2:1999SLOVENSKI

STANDARD

INTERNATIONAL STANDARD IS0 2768-2 First edition 1989-l l-15 General tolerances - Part 2: Geometrical tolerances for features without individual tolerance indications Tolhances g&&ales - Partie 2: Tohances gkomhtriques pour 6lkments non affect&s de tolkances individuelles Reference number IS0 2768-2 : 1989 (E)

IS0 2768-2 : 1989 (El Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 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, govern- mental and non-governmental, in liaison with ISO, also take part in the work. IS0 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 approval before their acceptance as International Standards by the IS0 Council. They are approved in accordance with IS0 procedures requiring at least 75 % approval by the member bodies voting. International Standard IS0 2768-2 was prepared by Technical Committee ISO/TC 3, Limits and fits. This first edition of IS0 2768-2, together with IS0 2768-l : 1989, cancel and replace IS0 2768 : 1973. IS0 2768 consists of the following parts, under the general title Genera/ tolerances: - Part tolerance for 7 : Tolerances indications linear and angular dimensions without individual - Part cations 2: Geometrical tolerances for features without individual tolerance indi- Annexes A and B of this part of IS0 2768 are for information only. 0 IS0 198s All rights reserved. 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 the publisher. International Organization for Standardization Case postale 56 l CH-1211 Gen&ve 20 l Switzerland Printed in Switzerland ii

Iso 2768-2 : 1989 (El Introduction All features on component parts always have a size and a geometrical shape. For the deviation of size and for the deviations of the geometrical characteristics (form, orientation and location) the function of the part requires limitations which, when exceeded, impair this function. The tolerancing on the drawing should be complete to ensure that the elements of size and geometry of all features are controlled, i.e. nothing shall be implied or left to judge- ment in the workshop or in the inspection department. The use of general tolerances this prerequisite is met. for size and geometry simplifies the task of ensuring that

This page intentionally left blank

INTERNATIONAL STANDARD IS0 2768-2 : 1989 (El General tolerances - Part 2: Geometrical tolerances for features without individual tolerance indications 1 Scope This part of IS0 2768 is intended to simplify drawing indica- tions and specifies general geometrical tolerances to control those features on the drawing which have no respective in- dividual indication. It specifies general geometrical tolerances in three tolerance classes. This part of IS0 2768 mainly applies to features which are pro- duced by removal of material. Its application to features manufactured by other processes is possible; however, special examination is required to ascertain whether the customary workshop accuracy lies within the general geometrical toler- ances specified in this part of IS0 2768. 2 General When selecting the tolerance class, the respective customary workshop accuracy has to be taken into consideration, If smaller geometrical tolerances are required or larger geometrical tolerances are permissible and more economical for any individual feature, such tolerances should be indicated directly in accordance with IS0 1101 (see clause A.2). General geometrical tolerances in accordance with this part of IS0 2768 apply when drawings or associated specifications refer to this part of IS0 2768 in accordance with clause 6. They apply to features which do not have respective individual geometrical tolerance indications. General geometrical tolerances apply to all geometrical toler- ance characteristics, excluding cylindricity, profile of any line, profile of any surface, angularity, coaxiality, positional toler- ances and total run-out. In any event, general geometrical tolerances in accordance with this part of IS0 2768 should be used when the fundamental tolerancing principle in accordance with IS0 8015 is used and indicated on the drawing (see clause B. 1). 3 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of IS0 2768. 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 IS0 2768 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IS0 1101 : 1983, Technical drawings - Geometrical toleranc- ing - Tolerancing of form, orientation, location and run-out - Generalities, definitions, symbols, indications on drawings. IS0 2768-l : 1989, General tolerances - Part 7 : Tolerances for linear and angular dimensions without individual tolerance indi- cations. IS0 5459 : 1981, Technical drawings - Geometrical toleranc- ing - Datums and datum-systems for geometrical tolerances. IS0 8015 : 1985, Technical drawings - Fundamental toleranc- ing principle. 4 Definitions For the purposes of this part of IS0 2768, the definitions for geometrical tolerances given in IS0 1101 and IS0 5459 apply. 5 General geometrical tolerances (see also clause B. 1) 5.1 Tolerances for single features 5.1 .l Straightness and flatness The general tolerances on straightness and flatness are given in table 1. When a tolerance is selected from table 1, it shall be based, in the case of straightness, on the length of the cor- responding line and, in the case of flatness, on the longer lateral length of the surface, or the diameter of the circular sur- face. 1

IS0 2768-2 : 1989 (I3 Table 1 - General tolerances on straightness 5.2.3 Perpendicularity and flatness Values in millimetres Straightness and flatness tolerances for ranges of nominal lengths Toler- ance class The general tolerances on perpendicularity are given in table 2. The longer of the two sides forming the right angle shall be taken as the datum; if the sides are of equal nominal length, either may be taken as the datum. Table 2 - General tolerances on perpendicularity Values in millimetres 0,oz 1 0,05 ) 0,l 1 0,2 ) 0,3 1 0,4 0,05 ) 0,l 1 0,2 ) 0,4 1 0,6 1 Ok3 H Perpendicularity tolerances for ranges of nominal lengths of the shorter side up to loo I over 100 over 300 over 1 000 up to 300 up to 1 ooo up to 3 ooo K Toler- ance class H K L w I 02 1 0,4 ) 0,8 1 I,2 ) 1,6 L 0,2[ 0,3 ( 0,4 1 0,5 014 I 0,6 I 018 I 1 5.1.2 Circularity (46 1 115 2 The general tolerance on circularity is equal to the numerical value of the diameter tolerance, but in no case shall it be greater than the respective tolerance value for circular radial run-out given in table 4 (see examples in clause B.2). 5.2.4 Symmetry The general tolerances on symmetry are given in table 3. The longer of the two features shall be taken as the datum; if the features are of equal nominal length, either may be taken as the datum. 5.1.3 Cylindricity General tolerances on cylindricity are not specified. NOTE - The general tolerances on symmetry apply where - at least one of the two features has a median plane, or - the axes of the two features are perpendicular to each other. See examples in clause B.5. NOTES 1 The cylindricity deviation comprises three components : circularity deviation, straightness deviation and parallelism deviation of opposite generator lines. Each of these components is controlled by its in- dividually indicated or its general tolerance. Table 3 - General tolerances on symmetry Values in millimetres 2 If, for functional reasons, the cylindricity deviation has to be smaller than the combined effect (see clause B.3) of the general tolerances on circularity, straightness and parallelism, an individual cylindricity toler- ance in accordance with IS0 1101 should be indicated for the feature concerned. 1 Toler- 1 Symmetry tolerances for ranges of nominal lengths ante class to loo over 100 over 300 over 1 000 up up to 300 up to 1 ooo up to 3 ooo \ Sometimes, e.g. in the case of a fit, the indication of the envelope requirement 0 E is appropriate. I H I I W3 1 I L I W 1 I L5 I 2 5.2 Tolerances for related features 5.2.1 General 5.2.5 Coaxiality The tolerances specified in 5.2.2 to 5.2.6 apply to all features which are in relation to one another and which have no respec- tive individual indication. General tolerances on coaxiality are not specified. NOTE - The deviation in coaxiality may, in an extreme case, be as great as the tolerance value for circular radial run-out given in table 4, since the deviation in radial run-out comprises the deviation in coaxial- ity and the deviation in circularity. 5.2.2 Parallelism The general tolerance on parallelism is equal to the numerical value of the size tolerance or the flatness/straightness toler- ance, whichever is the greater. The longer of the two features shall be taken as the datum; if the features are of equal nominal length, either may be taken as the datum (see clause B.4). 5.2.6 Circular run-out The general tolerances on circular run-out (radial, axial and any surface of revolution) are given in table 4. 2

Iso 2768-2 : 1989 0 For general tolerances on circular run-out, the bearing surfaces shall be taken as the datum if they are designated as such. O

...

INTERNATIONAL IS0
2768-2
STANDARD
First edition
1989-l l-15
General tolerances -
Part 2:
Geometrical tolerances for features without individual
tolerance indications
Tolhances g&&ales -
Partie 2: Tohances gkomhtriques pour 6lkments non affect&s de tolkances
individuelles
Reference number
IS0 2768-2 : 1989 (E)
---------------------- Page: 1 ----------------------
IS0 2768-2 : 1989 (El
Foreword

IS0 (the International Organization for Standardization) is a worldwide federation of

national standards bodies (IS0 member bodies). The work of preparing International

Standards is normally carried out through IS0 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, govern-

mental and non-governmental, in liaison with ISO, also take part in the work. IS0

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 approval before their acceptance as International Standards by

the IS0 Council. They are approved in accordance with IS0 procedures requiring at

least 75 % approval by the member bodies voting.
International Standard IS0 2768-2 was prepared by Technical Committee ISO/TC 3,
Limits and fits.

This first edition of IS0 2768-2, together with IS0 2768-l : 1989, cancel and replace

IS0 2768 : 1973.

IS0 2768 consists of the following parts, under the general title Genera/ tolerances:

without
- Part 7 : Tolerances for linear and angular dimensions individual
indications
tolerance
features without individual tolerance indi-
- Part 2: Geometrical tolerances for
cations
Annexes A and B of this part of IS0 2768 are for information only.
0 IS0 198s

All rights reserved. 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 the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Gen&ve 20 l Switzerland
Printed in Switzerland
---------------------- Page: 2 ----------------------
Iso 2768-2 : 1989 (El
Introduction

All features on component parts always have a size and a geometrical shape. For the

deviation of size and for the deviations of the geometrical characteristics (form,

orientation and location) the function of the part requires limitations which, when

exceeded, impair this function.

The tolerancing on the drawing should be complete to ensure that the elements of size

and geometry of all features are controlled, i.e. nothing shall be implied or left to judge-

ment in the workshop or in the inspection department.

use of general tolerances for size and geometry simplifies the task of ensuring that

The
this prerequisite is met.
---------------------- Page: 3 ----------------------
This page intentionally left blank
---------------------- Page: 4 ----------------------
IS0 2768-2 : 1989 (El
INTERNATIONAL STANDARD
General tolerances -
Part 2:
Geometrical tolerances for features without individual
tolerance indications
IS0 2768. At the time of publication, the editions indicated
1 Scope
were valid. All standards are subject to revision, and parties to
agreements based on this part of IS0 2768 are encouraged to
This part of IS0 2768 is intended to simplify drawing indica-
investigate the possibility of applying the most recent editions
tions and specifies general geometrical tolerances to control

those features on the drawing which have no respective in- of the standards indicated below. Members of IEC and IS0

maintain registers of currently valid International Standards.
dividual indication. It specifies general geometrical tolerances in
three tolerance classes.
IS0 1101 : 1983, Technical drawings - Geometrical toleranc-
This part of IS0 2768 mainly applies to features which are pro-
ing - Tolerancing of form, orientation, location and run-out -
duced by removal of material. Its application to features
Generalities, definitions, symbols, indications on drawings.
manufactured by other processes is possible; however, special
examination is required to ascertain whether the customary
IS0 2768-l : 1989, General tolerances - Part 7 : Tolerances for
workshop accuracy lies within the general geometrical toler-
linear and angular dimensions without individual tolerance indi-
ances specified in this part of IS0 2768.
cations.
IS0 5459 : 1981, Technical drawings - Geometrical toleranc-
2 General
ing - Datums and datum-systems for geometrical tolerances.
When selecting the tolerance class, the respective customary
IS0 8015 : 1985, Technical drawings - Fundamental toleranc-
workshop accuracy has to be taken into consideration, If
or larger ing principle.
smaller geometrical tolerances are required
geometrical tolerances are permissible and more economical for
any individual feature, such tolerances should be indicated
directly in accordance with IS0 1101 (see clause A.2).
4 Definitions
General geometrical tolerances in accordance with this part of
IS0 2768 apply when drawings or associated specifications
For the purposes of this part of IS0 2768, the definitions for
refer to this part of IS0 2768 in accordance with clause 6. They
geometrical tolerances given in IS0 1101 and IS0 5459 apply.
apply to features which do not have respective individual
geometrical tolerance indications.
General geometrical tolerances apply to all geometrical toler-
5 General geometrical tolerances
ance characteristics, excluding cylindricity, profile of any line,
(see also clause B. 1)
profile of any surface, angularity, coaxiality, positional toler-
ances and total run-out.
5.1 Tolerances for single features
In any event, general geometrical tolerances in accordance with
this part of IS0 2768 should be used when the fundamental
5.1 .l Straightness and flatness
tolerancing principle in accordance with IS0 8015 is used and
indicated on the drawing (see clause B. 1).
The general tolerances on straightness and flatness are given in
table 1. When a tolerance is selected from table 1, it shall be
based, in the case of straightness, on the length of the cor-
3 Normative references
responding line and, in the case of flatness, on the longer
lateral length of the surface, or the diameter of the circular sur-
The following standards contain provisions which, through
face.
reference in this text, constitute provisions of this part of
---------------------- Page: 5 ----------------------
IS0 2768-2 : 1989 (I3
5.2.3 Perpendicularity
Table 1 - General tolerances on straightness
and flatness
The general tolerances on perpendicularity are given in table 2.
Values in millimetres
The longer of the two sides forming the right angle shall be
Straightness and flatness tolerances for ranges
taken as the datum; if the sides are of equal nominal length,
of nominal lengths
either may be taken as the datum.
Toler-
ance
class
Table 2 - General tolerances on perpendicularity
Values in millimetres
H 0,oz 1 0,05 ) 0,l 1 0,2 ) 0,3 1 0,4
Perpendicularity tolerances for ranges of
K 0,05 ) 0,l 1 0,2 ) 0,4 1 0,6 1 Ok3
Toler- nominal lengths of the shorter side
ance
w 02 1 0,4 ) 0,8 1 I,2 ) 1,6
class over 100 over 300 over 1 000
up to loo
up to 3 ooo
up to 300 up to 1 ooo
H 0,2[ 0,3 ( 0,4 1 0,5
K 1
014 0,6 018
I I I
5.1.2 Circularity
L 1 2
(46 115
The general tolerance on circularity is equal to the numerical
value of the diameter tolerance, but in no case shall it be greater
than the respective tolerance value for circular radial run-out
5.2.4 Symmetry
given in table 4 (see examples in clause B.2).
The general tolerances on symmetry are given in table 3. The
longer of the two features shall be taken as the datum; if the
5.1.3 Cylindricity
features are of equal nominal length, either may be taken as the
datum.
General tolerances on cylindricity are not specified.
NOTE - The general tolerances on symmetry apply where
NOTES
at least one of the two features has a median plane, or
the axes of the two features are perpendicular to each other.
1 The cylindricity deviation comprises three components : circularity

deviation, straightness deviation and parallelism deviation of opposite See examples in clause B.5.

generator lines. Each of these components is controlled by its in-
dividually indicated or its general tolerance.
Table 3 - General tolerances on symmetry
2 If, for functional reasons, the cylindricity deviation has to be smaller
Values in millimetres
than the combined effect (see clause B.3) of the general tolerances on
Symmetry tolerances for ranges of
circularity, straightness and parallelism, an individual cylindricity toler-
1 Toler- 1 nominal lengths
ance in accordance with IS0 1101 should be indicated for the feature
ante
concerned.
class
over 100 over 300 over 1 000
up to loo
up to 300 up to
1 ooo up to 3 ooo
Sometimes, e.g. in the case of a fit, the indication of the envelope
requirement
E is appropriate. I H I
I W3 1
L 2
W 1 L5
I I I I
5.2 Tolerances for related features
5.2.1 General
5.2.5 Coaxiality
The tolerances specified in 5.2.2 to 5.2.6 apply to all features
which are in relation to one another and which have no respec-
General tolerances on coaxiality are not specified.
tive individual indication.
NOTE - The deviation in coaxiality may, in an extreme case, be as
great as the tolerance value for circular radial run-out given in table 4,
since the deviation in radial run-out comprises the deviation in coaxial-
5.2.2 Parallelism
ity and the deviation in circularity.
The general tolerance on parallelism is equal to the numerical
5.2.6 Circular run-out
value of the size tolerance or the flatness/straightness toler-
ance, whichever is the greater. The longer of the two features

shall be taken as the datum; if the features are of equal nominal The general tolerances on circular run-out (radial, axial and any

length, either may be taken as the datum (see clause B.4). surface of revolution) are given in table 4.

---------------------- Page: 6 ----------------------
Iso 2768-2 : 1989 0

For general tolerances on circular run-out, the bearing surfaces In this case the general tolerances for angular dimensions in ac-

cordance with IS0 2768-l do not apply to right angles (900),
shall be taken as the datum if they are designated as such.

Otherwise, for circular radial run-out, the longer of the two which are implied but not indicated, because this part of

IS0 2768 specifies ge
...

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Tolérances générales -- Partie 2: Tolérances géométriques pour éléments non affectés de tolérances individuellesGeneral tolerances -- Part 2: Geometrical tolerances for features without individual tolerance indications17.040.10Tolerance in ujemiLimits and fitsICS:Ta slovenski standard je istoveten z:ISO 2768-2:1989SIST ISO 2768-2:199en01-QRYHPEHU-199SIST ISO 2768-2:199SLOVENSKI

STANDARD
SIST ISO 2768-2:1995

INTERNATIONAL STANDARD IS0 2768-2 First edition 1989-l l-15 General tolerances - Part 2: Geometrical tolerances for features without individual tolerance indications Tolhances g&&ales - Partie 2: Tohances gkomhtriques pour 6lkments non affect&s de tolkances individuelles Reference number IS0 2768-2 : 1989 (E) SIST ISO 2768-2:1995

IS0 2768-2 : 1989 (El Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 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, govern- mental and non-governmental, in liaison with ISO, also take part in the work. IS0 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 approval before their acceptance as International Standards by the IS0 Council. They are approved in accordance with IS0 procedures requiring at least 75 % approval by the member bodies voting. International Standard IS0 2768-2 was prepared by Technical Committee ISO/TC 3, Limits and fits. This first edition of IS0 2768-2, together with IS0 2768-l : 1989, cancel and replace IS0 2768 : 1973. IS0 2768 consists of the following parts, under the general title Genera/ tolerances: - Part tolerance for 7 : Tolerances indications linear and angular dimensions without individual - Part cations 2: Geometrical tolerances for features without individual tolerance indi- Annexes A and B of this part of IS0 2768 are for information only. 0 IS0 198s All rights reserved. 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 the publisher. International Organization for Standardization Case postale 56 l CH-1211 Gen&ve 20 l Switzerland Printed in Switzerland ii SIST ISO 2768-2:1995

Iso 2768-2 : 1989 (El Introduction All features on component parts always have a size and a geometrical shape. For the deviation of size and for the deviations of the geometrical characteristics (form, orientation and location) the function of the part requires limitations which, when exceeded, impair this function. The tolerancing on the drawing should be complete to ensure that the elements of size and geometry of all features are controlled, i.e. nothing shall be implied or left to judge- ment in the workshop or in the inspection department. The use of general tolerances this prerequisite is met. for size and geometry simplifies the task of ensuring that SIST ISO 2768-2:1995

This page intentionally left blank SIST ISO 2768-2:1995

INTERNATIONAL STANDARD IS0 2768-2 : 1989 (El General tolerances - Part 2: Geometrical tolerances for features without individual tolerance indications 1 Scope This part of IS0 2768 is intended to simplify drawing indica- tions and specifies general geometrical tolerances to control those features on the drawing which have no respective in- dividual indication. It specifies general geometrical tolerances in three tolerance classes. This part of IS0 2768 mainly applies to features which are pro- duced by removal of material. Its application to features manufactured by other processes is possible; however, special examination is required to ascertain whether the customary workshop accuracy lies within the general geometrical toler- ances specified in this part of IS0 2768. 2 General When selecting the tolerance class, the respective customary workshop accuracy has to be taken into consideration, If smaller geometrical tolerances are required or larger geometrical tolerances are permissible and more economical for any individual feature, such tolerances should be indicated directly in accordance with IS0 1101 (see clause A.2). General geometrical tolerances in accordance with this part of IS0 2768 apply when drawings or associated specifications refer to this part of IS0 2768 in accordance with clause 6. They apply to features which do not have respective individual geometrical tolerance indications. General geometrical tolerances apply to all geometrical toler- ance characteristics, excluding cylindricity, profile of any line, profile of any surface, angularity, coaxiality, positional toler- ances and total run-out. In any event, general geometrical tolerances in accordance with this part of IS0 2768 should be used when the fundamental tolerancing principle in accordance with IS0 8015 is used and indicated on the drawing (see clause B. 1). 3 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of IS0 2768. 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 IS0 2768 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IS0 1101 : 1983, Technical drawings - Geometrical toleranc- ing - Tolerancing of form, orientation, location and run-out - Generalities, definitions, symbols, indications on drawings. IS0 2768-l : 1989, General tolerances - Part 7 : Tolerances for linear and angular dimensions without individual tolerance indi- cations. IS0 5459 : 1981, Technical drawings - Geometrical toleranc- ing - Datums and datum-systems for geometrical tolerances. IS0 8015 : 1985, Technical drawings - Fundamental toleranc- ing principle. 4 Definitions For the purposes of this part of IS0 2768, the definitions for geometrical tolerances given in IS0 1101 and IS0 5459 apply. 5 General geometrical tolerances (see also clause B. 1) 5.1 Tolerances for single features 5.1 .l Straightness and flatness The general tolerances on straightness and flatness are given in table 1. When a tolerance is selected from table 1, it shall be based, in the case of straightness, on the length of the cor- responding line and, in the case of flatness, on the longer lateral length of the surface, or the diameter of the circular sur- face. 1 SIST ISO 2768-2:1995

IS0 2768-2 : 1989 (I3 Table 1 - General tolerances on straightness 5.2.3 Perpendicularity and flatness Values in millimetres Straightness and flatness tolerances for ranges of nominal lengths Toler- ance class The general tolerances on perpendicularity are given in table 2. The longer of the two sides forming the right angle shall be taken as the datum; if the sides are of equal nominal length, either may be taken as the datum. Table 2 - General tolerances on perpendicularity Values in millimetres 0,oz 1 0,05 ) 0,l 1 0,2 ) 0,3 1 0,4 0,05 ) 0,l 1 0,2 ) 0,4 1 0,6 1 Ok3 H Perpendicularity tolerances for ranges of nominal lengths of the shorter side up to loo I over 100 over 300 over 1 000 up to 300 up to 1 ooo up to 3 ooo K Toler- ance class H K L w I 02 1 0,4 ) 0,8 1 I,2 ) 1,6 L 0,2[ 0,3 ( 0,4 1 0,5 014 I 0,6 I 018 I 1 5.1.2 Circularity (46 1 115 2 The general tolerance on circularity is equal to the numerical value of the diameter tolerance, but in no case shall it be greater than the respective tolerance value for circular radial run-out given in table 4 (see examples in clause B.2). 5.2.4 Symmetry The general tolerances on symmetry are given in table 3. The longer of the two features shall be taken as the datum; if the features are of equal nominal length, either may be taken as the datum. 5.1.3 Cylindricity General tolerances on cylindricity are not specified. NOTE - The general tolerances on symmetry apply where - at least one of the two features has a median plane, or - the axes of the two features are perpendicular to each other. See examples in clause B.5. NOTES 1 The cylindricity deviation comprises three components : circularity deviation, straightness deviation and parallelism deviation of opposite generator lines. Each of these components is controlled by its in- dividually indicated or its general tolerance. Table 3 - General tolerances on symmetry Values in millimetres 2 If, for functional reasons, the cylindricity deviation has to be smaller than the combined effect (see clause B.3) of the general tolerances on circularity, straightness and parallelism, an individual cylindricity toler- ance in accordance with IS0 1101 should be indicated for the feature concerned. 1 Toler- 1 Symmetry tolerances for ranges of nominal lengths ante class to loo over 100 over 300 over 1 000 up up to 300 up to 1 ooo up to 3 ooo \ Sometimes, e.g. in the case of a fit, the indication of the envelope requirement 0 E is appropriate. I H I I W3 1 I L I W 1 I L5 I 2 5.2 Tolerances for related features 5.2.1 General 5.2.5 Coaxiality The tolerances specified in 5.2.2 to 5.2.6 apply to all features which are in relation to one another and which have no respec- tive individual indication. General tolerances on coaxiality are not specified. NOTE - The deviation in coaxiality may, in an extreme case, be as great as the tolerance value for circular radial run-out given in table 4, since the deviation in radial run-out comprises the deviation in coaxial- ity and the deviation in circularity. 5.2.2 Parallelism The general tolerance on parallelism is equal to the numerical value of the size tolerance or the flatness/straightness toler- ance, whichever is the greater. The longer of the two features shall be taken as the datum; if the features are of equal nominal length, either may be taken as the datum (see clause B.4). 5.2.6 Circular run-out The general tolerances on circular run-out (radial, axial and any surface of revolution) are given in table 4. 2 SIST ISO 2768-2:1995

Iso 2768-2 : 1989 0 For general tolerances on circular run-out, the bearing surfaces shall be taken as the datum if they are designated

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