Castings -- System of dimensional tolerances and machining allowances

Applies to cast metals and their alloys produced by various casting manufacturing processes. Is applicable both to general tolerances and/or required machining allowances given on a drawing and to individual tolerances and/or required machining allowances which are shown immediately following a specific dimension. The system specified applies when the foundry provides the pattern or die equipment or accepts responsibility for proving it.

Pièces moulées -- Système de tolérances dimensionnelles et surépaisseurs d'usinage

Ulitki - Sistem toleranc mer in dodatki za mehansko obdelavo

General Information

Status
Withdrawn
Publication Date
31-Oct-1995
Withdrawal Date
13-Nov-2013
Current Stage
9900 - Withdrawal (Adopted Project)
Start Date
14-Nov-2013
Due Date
07-Dec-2013
Completion Date
14-Nov-2013

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IS0
INTERNATIONAL
8062
STANDARD
Second edition
I 994-04-01
Castings - System of dimensional
tolerances and machining allowances
Pi&es moul&es - Systhme de tokrances dimensionnelies et
sur6paisseurs d ‘usinage
Reference number
IS0 8062: 1994(E)
---------------------- Page: 1 ----------------------
IS0 8062: 1994(E)
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, governmental
and non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission
(I EC) 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 IS0 8062 was prepared by Technical Committee
lSO/TC 3, Limits and fits.
This second edition cancels and replaces the first edition
(IS0 8062:1984), which has been technically revised.
Annexes A, B and C of this International Standard are for information only.
0 IS0 1994

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 the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
---------------------- Page: 2 ----------------------
0 IS0
IS0 8062: 1994(E)
Introduction
This International Standard relates to a system of tolerance grades and
machining allowance grades for cast metals and their alloys.
The tolerance specified for a casting may determine the casting method.
It is therefore recommended, before the design or the order is finalized,
that the customer liaise with the foundry to discuss
the proposed casting design and accuracy required;
machining requirements;
c) method of casting;
the number of castings to be manufactured;
the casting equipment involved;
f) any special requirements, for instance, datum target systems, individ-
ual dimensional tolerances, geometrical tolerances, fillet radii toler-
ances and individual machining allowances;
whether any other standard is more appropriate for the casting.
NOTE 1
Further investigation on metallic permanent moulds (gravity- and low-
pressure), pressure die castings and investment castings should be carried out.
Because the dimensional accuracy of a casting is related to production
factors, tolerance grades which can be achieved for various methods and
metals are described in annex A for
a) long series and mass production, where development, adjustment and
maintenance of casting equipment make it possible to achieve close
tolerances;
short series and single production.
Information on typical required machining allowance grades is given in
annex B.
---------------------- Page: 3 ----------------------
This page intentionally left blank
---------------------- Page: 4 ----------------------
IS0 8062: 1994(E)
INTERNATIONAL STANDARD 0 IS0
Castings - System of dimensional tolerances and
machining allowances
IS0 286-l : 1988, IS0 system of limits and fits -
1 Scope
Part I: Bases of tolerances, deviations and fits.
This International Standard specifies a system of tol-
IS0 1302:1992, Technical drawings - Method of in-
erance grades and required machining allowance
dicating s&ace texture.
grades for the dimensions of castings. It is applicable
to the dimensions of cast metals and their alloys
produced by various casting manufacturing processes
[but see also Introduction g) and clause 51.
This tnternational Standard applies both to general
3 Definitions
tolerances and/or required machining allowances
given on a drawing and to individual tolerances
For the purposes of this International Standard, the
and/or required machining allowances which are
following definitions apply.
shown immediately following a specific dimension
(see clause 11).
3.1 basic dimension: Dimension of a raw casting
before machining (see figure I), the necessary ma-
The system specified applies when the foundry pro-
chining allowance being included (see figure 2).
vides the pattern or die equipment or accepts re-
sponsibility for proving it.
Raw casting basic dimension
2 Normative references
---
The following standards contain provisions which,
through reference in this text, constitute provisions
of this International Standard. At the time of publi-
cation, the editions indicated were valid. All standards
are subject to revision, and parties to agreements
based on this International Standard are encouraged
to investigate the possibility of applying the most re-
cent editions of the standards indicated below.
Members of IEC and IS0 maintain registers of cur-

rently valid International Standards. Figure 1 - Drawing indications (see clause 4)

---------------------- Page: 5 ----------------------
0 IS0
IS0 8062: 1994(E)
With cylindrical features or machining on both sides,
the RMA is taken into account twice (see figures 5
and 6).
Finished dimension
3.4 mismatch: Relative displacement of surfaces of
a casting owing to inaccuracies in the constituent
parts of multipart moulds (see figure3).
RMA-
3.5 draft angle (taper): Additional slope of shaping
elements (e.g. on enveloping surfaces) necessary to
facilitate the removal of a casting from a mould or die,
or a pattern from a mould, or the parts of a permanent
mould from each other.
CT/2
4 Dimensioning
With the exception of dimensioning of wall thickness
Minimum limit of size
(where a chain of two dimensions may exist), chain
Maximum limit of size
- dimensioning shall be avoided.
5 Tolerance grades
Figure 2 - Tolerance limits
There are 16 casting tolerance grades, designated
CT1 to CT16 (see table 1).
Dimensions for which general tolerances are not
3.2 dimensional tolerance: [See IS0 286-I].
suitable shall be allocated individual tolerances.
While work is proceeding to obtain definite tolerance
3.3 required machining allowance, RMA: On raw
information for metallic permanent mould castings
castings, a material allowance to permit the removal

of the effects of casting on the surface by subsequent (gravity- and low-pressure), pressure die castings and

machining and to allow the achievement of the de- investment castings, other more appropriate tolerance

standards, e.g. national standards, may be employed
sired surface texture and the necessary accuracy of
for these particular processes.
dimension.
Maximum mismatch , _ Maximum mismatch
Minimum Limit of size
Ir= Z
Maximum limit of size
-c m
Figure 3 - Maximum mismatch
---------------------- Page: 6 ----------------------
0 IS0
IS0 8062:1994(E)
thickness in grades CT1 to CT15 shall be one grade
6 Mismatch
coarser than the general tolerance for other dimen-

Unless otherwise specified, mismatch shall lie within sions; for example, if there is a general tolerance on

the tolerance shown in table 1 (see figure3). When it a drawing of CTlO, the tolerance on wall thicknesses

is important to restrict further the value of mismatch, shall be CT? 1.
the maximum value shall be stated on the drawing
(see 11 .I).
8 Tapered features
7 Wall thickness Where a design requires a tapered feature (e.g. fea-
ture with a draft angle), the tolerance shall be applied

Unless otherwise specified, the tolerance for wall symmetrically along the surface (see figure4).

Drawina indication
Interpretation
$= Ejxic dimension-]
Basic dimension
Taper +
Taper -
Taper *
Figure 4 -
Tolerance zone on tapered features
---------------------- Page: 7 ----------------------
@J IS0
IS0 8062:1994(E)

The drawing shall specify generally whether the taper When agreed between manufacturer and purchaser

the tolerance zone may be
shall be added to, subtracted from or averaged to the for specific reasons,
material, e.g. asymmetric. In such a case the tolerance shall be
stated individually, following the basic dimension.
taper +, figure4a)
taper -, figure 4 b)
10 Required machining allowances,
RMA
taper *, figure4c)
Tapers for particular surfaces arranged differently
from the general arrangement of taper of the drawing 10.1 General
shall be indicated individually at the surface, e.g.
Unless otherwise specified, the required machining
+ l allowance is valid for the entire raw casting, i.e. only
one value is specified for all surfaces to be machined,
For dimensions to be machined, “taper +” shall be
and this shall be selected from the appropriate di-
applied, irrespective of the general drawing specifica-
mension range according to the largest overall di-
tion for taper, in order that the finished dimensions
mension of the finished casting after final machining
can be achievable.
(see figure 9).
The maximum dimension of a feature, as cast, shall
9 Position of tolerance zone
not exceed the finished dimension plus the required
machining allowance plus the total casting tolerance
The tolerance zone, unless otherwise stated, shall be
(see figure 2 and figures 5 to 8). When applicable, the
symmetrically disposed with respect to a basic di-
taper shall be considered additionally, as shown in
mension, i.e. with one half on the positive side and
figure 4.
one half on the negative side (see figure2).
CT/4,_ + /-CT/4
F RMA
RMA
1 e
R=F+ZRMA+CT/Z
R = Raw casting basic dimension
F = Dimension after final machining
RMA = Required machining allowance
CT = Casting tolerance
Figure 5 - External machining of boss
---------------------- Page: 8 ----------------------
- -
CT/4
CT/4 R
RMA RMA
--c -
R=F-ZRMA-CT/Z
CT/Z CT/2
I-- --I
Internal machining
Figure 6 -
R=F
(= F - RMA + RMA - CT/4 + CT/4)
CT/Z CT/2
I-- L-l
Figure 7 - Machining of step dimension
R=F+RMA+CT/Z
Figure 8 - Machining on one side of feature
---------------------- Page: 9 ----------------------
0 IS0
IS0 8062: 1994(E)
b) if further restriction of the mismatch is required
(see clause 4);
EXAMPLE
“General tolerances IS0 8062 - CT12 - maxi-
mum mismatch 1,5”
if individual tolera rices are required fol
...

SLOVENSKI STANDARD
SIST ISO 8062:1995
01-november-1995
Ulitki - Sistem toleranc mer in dodatki za mehansko obdelavo
Castings -- System of dimensional tolerances and machining allowances

Pièces moulées -- Système de tolérances dimensionnelles et surépaisseurs d'usinage

Ta slovenski standard je istoveten z: ISO 8062:1994
ICS:
17.040.10 Tolerance in ujemi Limits and fits
SIST ISO 8062:1995 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST ISO 8062:1995
---------------------- Page: 2 ----------------------
SIST ISO 8062:1995
IS0
INTERNATIONAL
8062
STANDARD
Second edition
I 994-04-01
Castings - System of dimensional
tolerances and machining allowances
Pi&es moul&es - Systhme de tokrances dimensionnelies et
sur6paisseurs d ‘usinage
Reference number
IS0 8062: 1994(E)
---------------------- Page: 3 ----------------------
SIST ISO 8062:1995
IS0 8062: 1994(E)
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, governmental
and non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission
(I EC) 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 IS0 8062 was prepared by Technical Committee
lSO/TC 3, Limits and fits.
This second edition cancels and replaces the first edition
(IS0 8062:1984), which has been technically revised.
Annexes A, B and C of this International Standard are for information only.
0 IS0 1994

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 the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
---------------------- Page: 4 ----------------------
SIST ISO 8062:1995
0 IS0
IS0 8062: 1994(E)
Introduction
This International Standard relates to a system of tolerance grades and
machining allowance grades for cast metals and their alloys.
The tolerance specified for a casting may determine the casting method.
It is therefore recommended, before the design or the order is finalized,
that the customer liaise with the foundry to discuss
the proposed casting design and accuracy required;
machining requirements;
c) method of casting;
the number of castings to be manufactured;
the casting equipment involved;
f) any special requirements, for instance, datum target systems, individ-
ual dimensional tolerances, geometrical tolerances, fillet radii toler-
ances and individual machining allowances;
whether any other standard is more appropriate for the casting.
NOTE 1
Further investigation on metallic permanent moulds (gravity- and low-
pressure), pressure die castings and investment castings should be carried out.
Because the dimensional accuracy of a casting is related to production
factors, tolerance grades which can be achieved for various methods and
metals are described in annex A for
a) long series and mass production, where development, adjustment and
maintenance of casting equipment make it possible to achieve close
tolerances;
short series and single production.
Information on typical required machining allowance grades is given in
annex B.
---------------------- Page: 5 ----------------------
SIST ISO 8062:1995
This page intentionally left blank
---------------------- Page: 6 ----------------------
SIST ISO 8062:1995
IS0 8062: 1994(E)
INTERNATIONAL STANDARD 0 IS0
Castings - System of dimensional tolerances and
machining allowances
IS0 286-l : 1988, IS0 system of limits and fits -
1 Scope
Part I: Bases of tolerances, deviations and fits.
This International Standard specifies a system of tol-
IS0 1302:1992, Technical drawings - Method of in-
erance grades and required machining allowance
dicating s&ace texture.
grades for the dimensions of castings. It is applicable
to the dimensions of cast metals and their alloys
produced by various casting manufacturing processes
[but see also Introduction g) and clause 51.
This tnternational Standard applies both to general
3 Definitions
tolerances and/or required machining allowances
given on a drawing and to individual tolerances
For the purposes of this International Standard, the
and/or required machining allowances which are
following definitions apply.
shown immediately following a specific dimension
(see clause 11).
3.1 basic dimension: Dimension of a raw casting
before machining (see figure I), the necessary ma-
The system specified applies when the foundry pro-
chining allowance being included (see figure 2).
vides the pattern or die equipment or accepts re-
sponsibility for proving it.
Raw casting basic dimension
2 Normative references
---
The following standards contain provisions which,
through reference in this text, constitute provisions
of this International Standard. At the time of publi-
cation, the editions indicated were valid. All standards
are subject to revision, and parties to agreements
based on this International Standard are encouraged
to investigate the possibility of applying the most re-
cent editions of the standards indicated below.
Members of IEC and IS0 maintain registers of cur-

rently valid International Standards. Figure 1 - Drawing indications (see clause 4)

---------------------- Page: 7 ----------------------
SIST ISO 8062:1995
0 IS0
IS0 8062: 1994(E)
With cylindrical features or machining on both sides,
the RMA is taken into account twice (see figures 5
and 6).
Finished dimension
3.4 mismatch: Relative displacement of surfaces of
a casting owing to inaccuracies in the constituent
parts of multipart moulds (see figure3).
RMA-
3.5 draft angle (taper): Additional slope of shaping
elements (e.g. on enveloping surfaces) necessary to
facilitate the removal of a casting from a mould or die,
or a pattern from a mould, or the parts of a permanent
mould from each other.
CT/2
4 Dimensioning
With the exception of dimensioning of wall thickness
Minimum limit of size
(where a chain of two dimensions may exist), chain
Maximum limit of size
- dimensioning shall be avoided.
5 Tolerance grades
Figure 2 - Tolerance limits
There are 16 casting tolerance grades, designated
CT1 to CT16 (see table 1).
Dimensions for which general tolerances are not
3.2 dimensional tolerance: [See IS0 286-I].
suitable shall be allocated individual tolerances.
While work is proceeding to obtain definite tolerance
3.3 required machining allowance, RMA: On raw
information for metallic permanent mould castings
castings, a material allowance to permit the removal

of the effects of casting on the surface by subsequent (gravity- and low-pressure), pressure die castings and

machining and to allow the achievement of the de- investment castings, other more appropriate tolerance

standards, e.g. national standards, may be employed
sired surface texture and the necessary accuracy of
for these particular processes.
dimension.
Maximum mismatch , _ Maximum mismatch
Minimum Limit of size
Ir= Z
Maximum limit of size
-c m
Figure 3 - Maximum mismatch
---------------------- Page: 8 ----------------------
SIST ISO 8062:1995
0 IS0
IS0 8062:1994(E)
thickness in grades CT1 to CT15 shall be one grade
6 Mismatch
coarser than the general tolerance for other dimen-

Unless otherwise specified, mismatch shall lie within sions; for example, if there is a general tolerance on

the tolerance shown in table 1 (see figure3). When it a drawing of CTlO, the tolerance on wall thicknesses

is important to restrict further the value of mismatch, shall be CT? 1.
the maximum value shall be stated on the drawing
(see 11 .I).
8 Tapered features
7 Wall thickness Where a design requires a tapered feature (e.g. fea-
ture with a draft angle), the tolerance shall be applied

Unless otherwise specified, the tolerance for wall symmetrically along the surface (see figure4).

Drawina indication
Interpretation
$= Ejxic dimension-]
Basic dimension
Taper +
Taper -
Taper *
Figure 4 -
Tolerance zone on tapered features
---------------------- Page: 9 ----------------------
SIST ISO 8062:1995
@J IS0
IS0 8062:1994(E)

The drawing shall specify generally whether the taper When agreed between manufacturer and purchaser

the tolerance zone may be
shall be added to, subtracted from or averaged to the for specific reasons,
material, e.g. asymmetric. In such a case the tolerance shall be
stated individually, following the basic dimension.
taper +, figure4a)
taper -, figure 4 b)
10 Required machining allowances,
RMA
taper *, figure4c)
Tapers for particular surfaces arranged differently
from the general arrangement of taper of the drawing 10.1 General
shall be indicated individually at the surface, e.g.
Unless otherwise specified, the required machining
+ l allowance is valid for the entire raw casting, i.e. only
one value is specified for all surfaces to be machined,
For dimensions to be machined, “taper +” shall be
and this shall be selected from the appropriate di-
applied, irrespective of the general drawing specifica-
mension range according to the largest overall di-
tion for taper, in order that the finished dimensions
mension of the finished casting after final machining
can be achievable.
(see figure 9).
The maximum dimension of a feature, as cast, shall
9 Position of tolerance zone
not exceed the finished dimension plus the required
machining allowance plus the total casting tolerance
The tolerance zone, unless otherwise stated, shall be
(see figure 2 and figures 5 to 8). When applicable, the
symmetrically disposed with respect to a basic di-
taper shall be considered additionally, as shown in
mension, i.e. with one half on the positive side and
figure 4.
one half on the negative side (see figure2).
CT/4,_ + /-CT/4
F RMA
RMA
1 e
R=F+ZRMA+CT/Z
R = Raw casting basic dimension
F = Dimension after final machining
RMA = Required machining allowance
CT = Casting tolerance
Figure 5 - External machining of boss
---------------------- Page: 10 ----------------------
SIST ISO 8062:1995
- -
CT/4
...

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