ISO 8062-4:2023

Geometrical product specifications (GPS) - Dimensional and geometrical tolerances for moulded parts - Part 4: Rules and general tolerances for castings using profile tolerancing in a general datum system

This document specifies the rules for geometrical dimensioning and tolerancing of final moulded parts and parts machined out of moulded parts. It also specifies rules and conventions for the indications of these requirements in technical product documentation and specifies the proportions and dimensions of the graphical symbols to be used. This document provides symbols for identifying the relative completeness of the moulded features and parts. These graphical symbols differ from the graphical symbols for surface texture according to ISO 1302[1], which are notably larger. This document specifies general geometrical tolerances using surface profile tolerances related to a general datum system that remains on the final part. It also specifies machining allowances and draft angles (tapers) for castings in all cast metals and their alloys produced by various casting manufacturing processes. This document establishes the general principles for presentation of general geometrical tolerances that apply to 2D technical drawings in all disciplines and trades but which are also applicable to 3D applications. NOTE All figures are shown in 2D views only. When cast datum surfaces are machined, this document is not applicable. [1]Cancelled and replaced by ISO 21920-1.

Spécification géométrique des produits (GPS) — Tolérances dimensionnelles et géométriques pour les pièces moulées — Partie 4: Tolérances générales pour les pièces moulées par tolérancement de profil dans un système général de références spécifiées

General Information

• Status: Published
• Publication Date: 04-May-2023
• ICS: 17.040.10 - Limits and fits
• Technical Committee: ISO/TC 213 - Dimensional and geometrical product specifications and verification
• Drafting Committee: ISO/TC 213/WG 9 - Dimensional and geometrical tolerancing for castings
• Current Stage: 6060 - International Standard published
• Start Date: 05-May-2023
• Due Date: 25-Oct-2022
• Completion Date: 05-May-2023

Relations

• Revises: ISO 8062-4:2017 - Geometrical product specifications (GPS) - Dimensional and geometrical tolerances for moulded parts - Part 4: General tolerances for castings using profile tolerancing in a general datum system
• Effective Date: 23-Apr-2020

Overview

ISO 8062-4:2023 - Geometrical product specifications (GPS) - Part 4 - defines the rules and general tolerances for castings using profile tolerancing in a general datum system. The standard covers geometrical dimensioning and tolerancing (GD&T) for final moulded parts and parts machined from moulded parts, including conventions for graphical symbols, proportions of symbols, and presentation in technical product documentation. It specifies general surface profile tolerances tied to a general datum system that remains on the final part, plus required machining allowances (RMA) and draft angle (taper) grades for cast metals and alloys. NOTE: the standard is not applicable when cast datum surfaces are subsequently machined.

Key topics and technical requirements

• General tolerancing approach: Uses surface profile tolerances in a general datum system to control size, form, orientation and location for castings and moulded parts.
• Graphical symbols & presentation: Defines symbols and their proportions for product-definition indications (different and larger than surface texture symbols per ISO 21920-1).
• Product definition types: Clarifies single/combined product definitions and indicators for final moulded, intermediate machined, and final machined conditions.
• Machining allowance (RMA): Specifies general and individual RMA rules to ensure adequate material for secondary machining.
• Draft angles (tapers): Defines draft/taper grades and symbols, including symmetric/unsymmetrical tolerance zones.
• Rules and decision logic: Presents Rules A–I covering application of general tolerances, surface profile tolerances, datum system (RST), overrides, additional tolerances, machined condition, RMA, drafts, and wall thickness.
• 2D and 3D applicability: Primary figures are 2D, but tolerancing principles are applicable to 3D CAD/CAM and inspection workflows.
• Normative and informative annexes: Include symbol dimensions, calculation methods for nominal dimensions, example drawings, multiple tolerancing method and guidance on selecting tolerances and RMAs.

Practical applications and users

ISO 8062-4:2023 is essential for:

• Foundry and casting engineers specifying tolerances on casting drawings
• Design engineers and CAD modelers who must define cast part tolerances and draft requirements
• Manufacturing engineers setting machining allowances and process planning
• Quality, inspection and metrology teams verifying form and profile tolerances against a general datum system
• Procurement and suppliers producing castings to specified GPS requirements

Typical uses: preparing technical product documentation (2D drawings and 3D models), defining required machining allowance and draft angles, applying general surface profile tolerances, and ensuring consistent GD&T for cast and machined-from-casting parts.

Related standards

• ISO 1101, ISO 5458, ISO 5459 (GD&T fundamentals)
• ISO 8015 (fundamental rules of GPS) and ISO 14253-1 (decision rules)
• ISO 14638 (GPS matrix model)
• ISO 21920-1 (surface texture symbols - replaces ISO 1302)
• Other parts of ISO 8062 series (dimensional tolerances for moulded and cast parts)

Keywords: ISO 8062-4:2023, geometrical product specifications, GPS, castings, profile tolerancing, general datum system, moulded parts, machining allowance, draft angle, surface profile tolerance.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 8062-4
Second edition
2023-05
Geometrical product specifications
(GPS) — Dimensional and geometrical
tolerances for moulded parts —
Part 4:
Rules and general tolerances for
castings using profile tolerancing in a
general datum system
Spécification géométrique des produits (GPS) — Tolérances
dimensionnelles et géométriques pour les pièces moulées —
Partie 4: Tolérances générales pour les pièces moulées par
tolérancement de profil dans un système général de références
spécifiées
Reference number
© ISO 2023
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
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Graphical symbols . 5
5 Product definition type indicator . .6
5.1 Single and combined product definitions . 6
5.2 Final moulded part product definitions . 6
5.3 Intermediate machined moulded part product definitions . 7
5.4 Final machined moulded part product definition . 7
5.5 Identifier for machining by the supplier . 7
6 Product definition indications . 8
6.1 Surface texture symbols . 8
6.2 Part condition identifiers . 8
6.2.1 General . 8
6.2.2 Surface texture . 9
6.2.3 Linear sizes . . . 10
6.2.4 Linear dimensions and individually indicated dimensional tolerances . 10
6.2.5 Theoretically exact dimensions (TEDs). 10
6.2.6 Geometrical tolerances and datums . 10
6.3 Required machining allowance (RMA) .12
6.3.1 General .12
6.3.2 General RMA . 12
6.3.3 Individual RMA .12
6.4 Draft angles .12
7 Indication of general tolerances . .15
7.1 General tolerances according to this document . 15
7.2 General surface profile tolerance . 15
8 Types of specifications .15
8.1 General . 15
8.2 Specification of final moulded part condition . 16
8.2.1 Overview of specification of final moulded part condition . . 16
8.2.2 Specification of final moulded part condition by the casting calculation
method . 16
8.2.3 Specification of final moulded part condition by the multiple tolerancing
method . 16
8.3 Specification of intermediate machined moulded part conditions . 17
8.4 Specification of final machined moulded part condition . 17
9 Tolerancing .18
9.1 General . 18
9.2 Tolerancing of final moulded parts . 18
9.2.1 Recommendations. 18
9.2.2 Drafts . 18
9.3 Tolerancing of intermediate machined moulded parts . 18
9.4 Tolerancing of final machined moulded parts . 19
9.4.1 General . 19
9.4.2 Drafts . 19
9.4.3 Multiple tolerancing method . 19
10 Rules .20
iii
10.1 Rule A: Application of general tolerances for castings . 20
10.2 Rule B: General surface profile tolerances . 20
10.3 Rule C: General datum system RST . 20
10.4 Rule D: Tolerances overruling the general surface profile tolerances .20
10.5 Rule E: Additional tolerances. 21
10.6 Rule F: Machined condition . 21
10.7 Rule G: Required machining allowances (RMA) . 21
10.8 Rule H: Draft angle (taper) .22
10.9 Rule I: Wall thickness . 22
11 General tolerances .22
12 Required machining allowances (RMAs) .24
13 Draft angles .24
14 General product definition indication .27
Annex A (normative) Proportions and dimensions of graphical symbols .29
Annex B (informative) Proposed process for general tolerancing castings .32
Annex C (informative) Examples for the multiple tolerancing method .33
Annex D (informative) Drawing examples .35
Annex E (informative) Selection of general tolerances .41
Annex F (informative) Selection of required machining allowances (RMA) .42
Annex G (informative) Example of using general tolerances .43
Annex H (normative) Calculation of the nominal dimension of the moulded
condition — casting calculation method .46
Annex I (informative) Relationship to the GPS matrix model .49
Bibliography .50
iv
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 213, Dimensional and geometrical product
specifications and verification.
This second edition cancels and replaces the first edition (ISO 8062-4:2017), which has been technically
revised.
The main changes are as follows:
— overall clarification regarding better applicability according to the ISO GPS system;
— overall revision of tables and figures for plausibility;
— new symbols for draft angles with symmetrical/unsymmetrical tolerance zones as already included
in the model geometry or drawing outlines have been added;
— requirements for the indication in the product definition (new Clauses 5, 6 and 7) and types of
specifications (new Clause 8) have been added;
— Rule I concerning the wall thickness has been added;
— Clause 9 and Annex G have been added, expanding the information previously given in former
Annex A;
— new Annexes A, B and C have been added;
A list of all parts in the ISO 8062 series can be found on the ISO website.
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.
v
Introduction
This document is a geometrical product specification (GPS) standard and is to be regarded as a
complementary ISO GPS standard. It influences chain link B of the chain of standards on size, form,
orientation and location.
The ISO GPS matrix model given in ISO 14638 gives an overview of the ISO GPS system, of which this
document is a part. The fundamental rules of ISO GPS given in ISO 8015 apply to this document and
the default decision rules given in ISO 14253-1 apply to specifications made in accordance with this
document, unless otherwise indicated.
For more detailed information about the relation of this document to other standards and the GPS
matrix model, see Annex I.
This document gives terms and definitions and symbols for product definition indications for
tolerancing of moulded parts, which are to be used in addition to the usual standards on geometrical
product specifications (GPS), such as ISO 1101, ISO 5458 and ISO 5459.
According to this document, ± tolerances are only used for sizes and the following non-features of
size: wall thicknesses, fillets and chamfers. Positional tolerances are also applied for sizes specified
with ± tolerances. For all other tolerancing purposes, geometrical tolerances according to ISO 1101 are
used. For all other non-features of size, such as step dimension, ± tolerances are not recommended. See
the ISO 14405 series for background information.
This document defines a system of tolerance grades, draft angle (taper) grades and machining allowance
grades for cast metals and their alloys.
ISO/TS 8062-2 states, in relation to the accumulation method where general dimensional tolerances
according to ISO 8062-3 are used, that there is not yet a clearly defined way in the context of the
future system of ISO GPS standards to apply the rules for calculating the final moulded part nominal
dimensions from the final machined moulded part nominal dimensions, taking into account the
miscellaneous influences. One of the reasons for this problem is the lack of a proper workpiece datum
system.
The general dimensional tolerances apply independently from each other (without a datum system). It
is difficult or even impossible to assess what the overall shape of the workpiece can become.
The general dimensional tolerances (±tolerances) of ISO 8062-3 apply not only to sizes but also to centre
distances and dimensions defining profile contours. This is in contradiction to the ISO GPS rules (e.g.
ISO 14405-2).
The general tolerances of ISO 8062-4 are not in compliance with the rules of ISO 22081 with respect to
the general geometrical tolerancing.
Furthermore, with 3D CAD the nominal dimensions are not always visible in the model. As the general
dimensional tolerances depend on the nominal dimensions, they cannot be used anymore when only the
CAD model is available. To avoid these problems this document was developed as a parallel approach
fully conforming with the ISO GPS rules given in, for example, ISO 14405-2 by introducing profile
tolerancing and a datum system.
If there is no datum system specified or if the datum surfaces are to be machined after moulding then
only ISO 8062-3 can be applied.
For the development of a new product, it is strongly recommended that customer and foundry should
discuss and agree on the method of tolerancing to be applied to the product. This also includes casting
method, calculation methods, cast material and draft angles, which are crucial for the process.
vi
INTERNATIONAL STANDARD ISO 8062-4:2023(E)
Geometrical product specifications (GPS) — Dimensional
and geometrical tolerances for moulded parts —
Part 4:
Rules and general tolerances for castings using profile
tolerancing in a general datum system
1 Scope
This document specifies the rules for geometrical dimensioning and tolerancing of final moulded parts
and parts machined out of moulded parts. It also specifies rules and conventions for the indications of
these requirements in technical product documentation and specifies the proportions and dimensions
of the graphical symbols to be used.
This document provides symbols for identifying the relative completeness of the moulded features
and parts. These graphical symbols differ from the graphical symbols for surface texture according to
1)
ISO 1302 , which are notably larger.
This document specifies general geometrical tolerances using surface profile tolerances related to a
general datum system that remains on the final part. It also specifies machining allowances and draft
angles (tapers) for castings in all cast metals and their alloys produced by various casting manufacturing
processes.
This document establishes the general principles for presentation of general geometrical tolerances
that apply to 2D technical drawings in all disciplines and trades but which are also applicable to 3D
applications.
NOTE All figures are shown in 2D views only.
When cast datum surfaces are machined, this document is not applicable.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 129-1, Technical product documentation (TPD) — Presentation of dimensions and tolerances — Part 1:
General principles
ISO 1101, Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form,
orientation, location and run-out
ISO 1302, Geometrical Product Specifications (GPS) — Indication of surface texture in technical product
documentation
ISO 1660, Geometrical product specifications (GPS) — Geometrical tolerancing — Profile tolerancing
ISO 2692, Geometrical product specifications (GPS) — Geometrical tolerancing — Maximum material
requirement (MMR), least material requirement (LMR) and reciprocity requirement (RPR)
1) Cancelled and replaced by ISO 21920-1.
ISO 5458, Geometrical product specifications (GPS) — Geometrical tolerancing — Pattern and combined
geometrical specification
ISO 5459, Geometrical product specifications (GPS) — Geometrical tolerancing — Datums and datum
systems
ISO 7083, Technical product documentation — Symbols used in technical product documentation —
Proportions and dimensions
ISO 8015, Geometrical product specifications (GPS) — Fundamentals — Concepts, principles and rules
ISO 8062-1, Geometrical product specifications (GPS) — Dimensional and geometrical tolerances for
moulded parts — Part 1: Vocabulary
ISO 8785, Geometrical Product Specification (GPS) — Surface imperfections — Terms, definitions and
parameters
ISO 10135, Geometrical product specifications (GPS) — Drawing indications for moulded parts in technical
product documentation (TPD)
ISO 10579, Geometrical product specifications (GPS) — Dimensioning and tolerancing — Non-rigid parts
ISO 13715, Technical product documentation — Edges of undefined shape — Indication and dimensioning
ISO 14405-1, Geometrical product specifications (GPS) — Dimensional tolerancing — Part 1: Linear sizes
ISO 14405-2, Geometrical product specifications (GPS) — Dimensional tolerancing — Part 2: Dimensions
other than linear or angular sizes
ISO 14405-3, Geometrical product specifications (GPS) — Dimensional tolerancing — Part 3: Angular sizes
ISO 16792, Technical product documentation — Digital product definition data practices
ISO 21204, Geometrical product specifications (GPS) — Transition specification
ISO 22081, Geometrical product specifications (GPS) — Geometrical tolerancing — General geometrical
specifications and general size specifications
ISO 81714-1, Design of graphical symbols for use in the technical documentation of products — Part 1:
Basic rules
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1101, ISO 1660, ISO 2692,
ISO 5458, ISO 5459, ISO 8062-1, ISO 10135, ISO 10579 and ISO 16792 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
moulded feature
feature of a moulded part which has not been machined
3.2
intermediate machined feature
feature of a moulded part which has undergone some machining and which subsequently will be
machined to its final condition
Note 1 to entry: An intermediate machined feature is typically a roughly machined moulded feature (3.1).
Note 2 to entry: An intermediate machined feature can be used as a datum for subsequent machining of the
moulded part.
3.3
final machined feature
feature of a moulded part which has been machined to its final condition
3.4
final moulded part
moulded part after fettling (if any)
Note 1 to entry: A final moulded part only consists of features which are moulded and have not been finished
except by fettling.
3.5
intermediate machined moulded part
moulded part which has undergone some machining and which subsequently will be machined to its
final condition
Note 1 to entry: An intermediate machined moulded part consists of at least one moulded feature (3.1) to be
subsequently machined or at least one intermediate machined feature (3.2). In addition, it consists of moulded
features not to be machined (if any) and final machined features (3.3) (if any).
Note 2 to entry: An intermediate machined moulded part can be produced from a final moulded part (3.4) or from
another intermediate machined moulded part.
3.6
final machined moulded part
moulded part which has been machined to its final condition
Note 1 to entry: A final machined moulded part consists of final machined features (3.3) and can include moulded
features (3.1) not to be machined. A final machined moulded part cannot include intermediate machined moulded
features.
Note 2 to entry: A final machined moulded part can be produced from a final moulded part (3.4) or from an
intermediate machined moulded part (3.5).
3.7
moulded part condition
manufacturing stage of a moulded part
Note 1 to entry: Listed in chronological order of manufacturing, a moulded part can be in a final moulded part (3.4)
condition, intermediate machined moulded part (3.5) condition or final machined moulded part (3.6) condition.
Note 2 to entry: Only one final moulded part condition exists.
Note 3 to entry: Various intermediate machined moulded part conditions can exist.
Note 4 to entry: Only one final machined moulded part condition can exist.
Note 5 to entry: A moulded part does not need to exist in an intermediate machined moulded part condition
before the final machined moulded part condition.
Note 6 to entry: Heat treatment or straightening (correction of unintended distortion) can be carried out in any
moulded part condition.
3.8
product definition
drawing or a 3D model representing the product
3.9
single product definition
product definition (3.8) of a moulded part giving requirements for one moulded part condition (3.7) only
3.10
combined product definition
product definition of a moulded part giving requirements for more than one moulded part condition
(3.7)
3.11
draft angle
taper
value of inclination (angle) that is added to a geometrical feature of a pattern or mould to ensure the
removal of the pattern or moulded part from the mould
3.12
external draft angle
draft angle (3.11) on a surface that has no opposite surface in the direction outward of the part
Note 1 to entry: See Figure 1.
3.13
internal draft angle
draft angle (3.11) on a surface that has an opposite surface in the direction outward of the part
Note 1 to entry: See Figure 1.
Key
length of the external feature
L
length of the internal feature
L
external draft angle
α
e
internal draft angle
α
i
Figure 1 — External and internal draft angles
3.14
draft angle increasing the tolerance of feature(s)
draft angle (3.11) which is added to the model geometry and included in the tolerance zone
Note 1 to entry: See Figure 17 d).
3.15
general datum system RST
datum system according to ISO 5459, locking all degrees of freedom and used for the general tolerance
Note 1 to entry: Annex G provides an example of using general tolerances. For the general datum system RST, see
Figure G.2.
Note 2 to entry: It is recommended that the datum feature identifiers R, S, and T are used for the general datum
systems for moulded parts.
Note 3 to entry: It is recommended that a datum target system RST is used, see Figure G.1.
Note 4 to entry: The datum letters R, S, T are reserved for the general datum system, see 10.3.
3.16
wall thickness
minimum dimension between two surfaces (external and internal) enclosing solid material
Note 1 to entry: The surface can be planar, cylindrical, complex or any combination thereof.
4 Graphical symbols
Table 1 gives an overview of the graphical symbols used in this document. Their proportions and
dimensions shall be as specified in Annex A.
Table 1 — Graphical symbols
Symbol Description Source
a
moulded surface ISO 1302
a
machined surface ISO 1302
a
moulded or machined surface ISO 1302
surface profile tolerance
positional tolerance
ISO 1101
theoretically exact dimension
datum of datum target
ISO 5459
datum target, fixed, movable
Surfaces without tolerance indica-
tion:
indication of general tolerance 10.1, 10.2, 10.3
parting surface
ISO 10135
movable
parting surface
fixed
indication of draft angle with sym-
metrical tolerance zone as already
6.4
included in the model geometry or
drawing outlines
a
New symbols for surface roughness in accordance with the ISO 21920 series are being prepared.
TTaabblle 1 e 1 ((ccoonnttiinnueuedd))
Symbol Description Source
indication of a draft angle with
unsymmetrical tolerance zone as
6.4
already included in the model geom-
etry or drawing outlines
draft angle with symmetrical
ISO 10135
tolerance zone
draft angle with unsymmetrical
6.4
tolerance zone
moulded condition 5.2
intermediate (pre)machined 5.3
final machined 5.4
machining by supplier 5.5
a
New symbols for surface roughness in accordance with the ISO 21920 series are being prepared.
5 Product definition type indicator
5.1 Single and combined product definitions
The requirements for the three types of moulded part conditions (final moulded, intermediate machined
moulded and final machined moulded) can be specified on a combined product definition or separately
on single product definitions, as appropriate.
NOTE Some CAD systems allow the representation of multiple types of moulded part conditions in one CAD
model.
If use of the symbols in this document makes a combined product definition difficult to read, use single
product definitions instead.
Information as to which part condition or conditions the stated specifications on the product definition
apply shall be indicated on the product definition in accordance with 5.2, 5.3, 5.4 and 5.5. Therefore, the
product definition shall indicate which part condition(s) the stated specification applies to.
On combined product definitions, only the outline of the most advanced part condition for which the
product definition is valid shall be illustrated. Requirements for the most advanced condition and for
the preceding moulded part condition in question shall be stated.
5.2 Final moulded part product definitions
If the product definition specifies requirements on a final moulded part, the graphical symbol given in
Figure 2 shall be indicated in or near the drawing title block or defined in the product definition data
set.
Figure 2 — Graphical symbol for a final moulded part product definition
5.3 Intermediate machined moulded part product definitions
If the product definition specifies requirements on an intermediate machined moulded part, the
graphical symbol given in Figure 3 shall be indicated in or near the drawing title block or defined in the
product definition data set.
Figure 3 — Graphical symbol for an intermediate machined moulded part product definition
If more than one intermediate machined moulded part condition exists on the product definition, they
shall be numbered and indicated after the symbol (see Figure 4).
a) b) c)
Figure 4 — Examples of numbered intermediate machined moulded parts
If stating general tolerances on a single product definition of an intermediate machined moulded
part, for example by referencing ISO 8062-4 or by stating particular general tolerances, these general
tolerances apply to the moulded features in the intermediate machined moulded part condition only.
5.4 Final machined moulded part product definition
If the product definition states requirements on a final machined moulded part, the graphical symbol
given in Figure 5 shall be indicated in or near the title block or defined in the product definition data
set.
Figure 5 — Graphical symbol for final machined moulded part product definition
If stating general tolerances according to the ISO 8062 series, for example by referencing ISO 8062-4 for
castings, on a product definition of a final machined moulded part, these general tolerances apply to the
moulded surfaces in the final machined moulded part condition only (see also Clause 14).
5.5 Identifier for machining by the supplier
If there is, for some special reason, a need to identify which part condition specifications a supplier
is expected to meet, this can be indicated by the symbol as shown in Figure 6 after the drawing type
indicator (see Figure 7).
Figure 6 — Symbol for machining by the supplier
a) Combined drawing b) Single drawing c) Single drawing
Figure 7 — Example of SUP indication used together with the product definition type indicator
near the drawing title block
In any case, the written agreement between customer and foundry shall clearly state which part
condition and which specification the supplier is expected to meet, irrespective of other part conditions
and specifications appearing on the product definition.
6 Product definition indications
6.1 Surface texture symbols
On combined product definitions, each surface shall be indicated with only one surface texture symbol
according to the condition of the surface in question on the most advanced part condition stated on the
product definition.
6.2 Part condition identifiers
6.2.1 General
Three-part condition identifiers are used for identifying which part condition a specification applies to
(see Figure 8).
a) For final moulded b) For intermediate machined c) For final machined
Figure 8 — Part condition identifiers
The part condition identifier may be omitted on single product definitions.
The use of part condition identifiers is necessary on a combined product definition to state requirements
to different part conditions (final moulded, intermediate machined moulded, final machined moulded),
see Figure D.4. More than one intermediate machined moulded part condition may be specified. This
being the case, the intermediate machined moulded part condition is enumerated in consecutive
sequence according to the manufacturing processes.
When a specification is given without a part condition identifier, this specification applies to all part
conditions stated on the product definition.
On combined product definitions, requirements on features that remain as moulded in the most
advanced part condition according to the product definition may also be given. If not otherwise
specified, this type of specification applies to all part conditions according to the product definition, see
Figure 9.
When a specification is given with an intermediate part condition, this specification applies for all
subsequent part conditions if not otherwise specified.
6.2.2 Surface texture
On combined product definitions, surface texture requirements shall be indicated for each part
condition using the symbols as shown in Figure 9.
Product definition indication
Condition
final moulded
intermediate machined 1
intermediate machined 2
final machined
Figure 9 — Example of a surface texture indication on a combined product definition and its
interpretation
6.2.3 Linear sizes
The part condition to which the linear dimension applies shall be indicated by a part condition identifier
as shown in Figure 10, if necessary.
b) Intermediate machined c) Final machined moulded
a) Final moulded part
moulded part part
Figure 10 — Examples of nominal dimensions
6.2.4 Linear dimensions and individually indicated dimensional tolerances
The part condition to which the linear dimension with its tolerance applies shall be indicated by a part
condition identifier as shown in Figure 11, if necessary.
a) Final moulded part b) Intermediate machined c) Final machined moulded
moulded part part
Figure 11 — Examples of nominal dimensions with individual tolerances
6.2.5 Theoretically exact dimensions (TEDs)
The part condition to which the TED applies shall be indicated by a part condition identifier as shown in
Figure 12, if necessary.
a) Final moulded part b) Intermediate machined c) Final machined moulded
moulded part part
Figure 12 — Examples of TEDs
6.2.6 Geometrical tolerances and datums
The part condition to which the geometrical tolerance applies shall be indicated by a part condition
identifier as shown in Figure 13, if necessary.
a) Final moulded part b) Intermediate ma- c) Final machined d) Final machined
chined moulded part moulded part moulded part
NOTE The examples a) and c) need a toleranced size in addition (e.g. ∅ 10 ± 1).
Figure 13 — Examples of geometrical tolerances with datum references
The part condition identifier shall be indicated after the tolerance indicator. If the datum exists in
different part conditions than those specified by the surface texture symbol, the datum applies in that
part condition stated together with the tolerance value (see Figures 14 and 15).
If the datum is specified to a planar feature in the final moulded part condition and the feature has
a taper, the datum applies without the taper, i.e. the actual taper shall be removed mechanically or
virtually. If possible, planar surfaces with draft angles used as datums should be avoided.
Key
1 final moulded part 3 datum A of final moulded part
2 intermediate machined moulded part 4 datum A of intermediate machined moulded part
Figure 14 — Example of a datum indication in different part conditions with different datums
Key
1 final moulded part 3 datum A of final moulded part
2 intermediate machined moulded part 4 datum A of intermediate machined moulded part
Figure 15 — Example of a datum indication in different part conditions with same datum
When a geometrical tolerance specification is given without a part condition identifier, this specification
applies to all part conditions stated on the product definition.
6.3 Required machining allowance (RMA)
6.3.1 General
All RMA values, A , have no tolerance. If applied together with a TED, they shall be used as TED
RMA
values; if applied together with a size, they shall be used as nominal dimensions. When RMA is used as a
TED, the value shall be framed; when used together with a size, it shall not be framed.
6.3.2 General RMA
If a general RMA is to apply to all surfaces to be machined on the final moulded part, it shall be stated in
or near the drawing title block or defined in the product definition data set according to this document
(ISO 8062-4).
EXAMPLE General tolerances ISO 8062-4 RMA 6
Only one value is specified for all surfaces to be machined, and this value shall be selected from the
appropriate dimension range according to the largest overall dimension of the final moulded part.
Table 4 contains standardized RMAs.
6.3.3 Individual RMA
If a special RMA is to apply to an individual surface, it shall be indicated individually before the surface
texture symbol according to ISO 1302 (see Figure 16).
Figure 16 — Example for individual RMA
An individual RMA overrules a general RMA.
In sand casting, top surfaces sometimes need more machining allowance than other features. For these
surfaces, coarser required machining allowance grades (RMAGs) can be selected and then indicated
individually.
6.4 Draft angles
A draft angle itself has no tolerance. Suggested draft angle values are given in Tables 5 to 9. If applied
together with a TED, they shall be used as TED-angle values; if applied together with a size, they shall
be used as nominal angles.
There are four possible ways to indicate a draft angle:
a) as already included in the model geometry or drawing outlines [same result as c)] with the symbol
;
b) as already included in the model geometry or drawing outlines [same result as d)] with the symbol
;
c) by the symbol ;
d) by the symbol .
In case a), the general surface profile tolerance zone is located adjacent to the nominal surface that
includes the draft angles.
When the draft angles are already included in the nominal model or in the drawing outlines, it shall be
indicated in or near the drawing title block or defined in the product definition data set: “Draft angles
included with the tolerance zone of ”.
In case b), the general surface profile tolerance zone is located like in case d) for the whole nominal
model. When the draft angles are already included in the nominal model or in the drawing outlines, it
shall be indicated in or near the drawing title block or defined in the product definition data set: “Draft
angles included with the tolerance zone of ”.
In case c), the general surface profile tolerance zone is located adjacent to the surface when the draft
angles are added to the nominal model which excludes the draft a
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