Technical product documentation - General principles of representation - Part 2: Basic conventions for lines (ISO 128-2:2020)

This document establishes the types of lines used in technical drawings (e.g. diagrams, plans or
maps), their designations and their configurations, as well as general rules for the draughting of lines.
In addition, this document specifies general rules for the representation of leader and reference lines
and their components as well as for the arrangement of instructions on or at leader lines in technical
documents. Annexes have been provided for specific information on mechanical, construction and
shipbuilding technical drawings.
For the purposes of this document the term “technical drawing” is interpreted in the broadest
possible sense encompassing the total package of documentation specifying the product (workpiece,
subassembly, assembly).

Technische Produktdokumentation (TPD) - Allgemeine Grundlagen der Darstellung - Teil 2: Linien, Grundregeln (ISO 128-2:2020)

Dieses Dokument legt die Linientypen, die in Technischen Zeichnungen verwendet werden (z. B. Diagramme, Pläne oder Karten), ihre Bezeichnungen und ihre Konfigurationen sowie allgemeine Regeln für das Zeichnen von Linien, die in technischen Zeichnungen fest. Zudem legt dieses Dokument allgemeine Regeln zur Darstellung von Hinweis- und Bezugslinien und deren Komponenten sowie zur Anordnung von Anweisungen zu oder an Hinweislinien in technischen Dokumenten fest. Anhänge mit spezifischen Informationen zu mechanischen, Bau- und Schiffbauzeichnungen werden zur Verfügung gestellt.
Für die Anwendung dieses Dokuments muss der Begriff „technische Zeichnung“ so allgemein wie möglich ausgelegt werden und sämtliche Dokumentation zum Produkt umfassen (Werkstück, Unterbaugruppe, Baugruppe).

Documentation technique de produits - Principes généraux de représentation - Partie 2: Conventions de base pour les traits (ISO 128-2:2020)

Le présent document établit les types de traits utilisés dans les dessins techniques (par exemple schémas, plans ou cartes), leurs désignations et leurs configurations, ainsi que les règles générales pour le tracé de traits. De plus, le présent document spécifie des règles générales pour la représentation des lignes repères et traits de référence et leurs composants, ainsi que pour la disposition des instructions sur ou aux lignes repères dans les documents techniques. Des annexes ont été prévues pour des informations spécifiques sur les dessins industriels, dessins de construction et dessins de construction navale.
Pour les besoins du présent document, le terme «dessin technique» est interprété au sens le plus large possible, englobant l'ensemble de la documentation spécifiant le produit (pièce, sous-ensemble, ensemble).

Tehnična dokumentacija izdelkov - Splošna načela prikazovanja - 2. del: Osnovni dogovori za črte (ISO 128-2:2020)

General Information

Status
Published
Public Enquiry End Date
03-Nov-2019
Publication Date
10-Sep-2020
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
02-Sep-2020
Due Date
07-Nov-2020
Completion Date
11-Sep-2020

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SLOVENSKI STANDARD
SIST EN ISO 128-2:2020
01-oktober-2020
Nadomešča:
SIST EN ISO 128-20:2002
SIST EN ISO 128-21:2002
Tehnična dokumentacija izdelkov - Splošna načela prikazovanja - 2. del: Osnovni
dogovori za črte (ISO 128-2:2020)

Technical product documentation - General principles of representation - Part 2: Basic

conventions for lines (ISO 128-2:2020)

Technische Produktdokumentation (TPD) - Allgemeine Grundlagen der Darstellung - Teil

2: Linien, Grundregeln (ISO 128-2:2020)

Documentation technique de produits - Principes généraux de représentation - Partie 2:

Conventions de base pour les traits (ISO 128-2:2020)
Ta slovenski standard je istoveten z: EN ISO 128-2:2020
ICS:
01.110 Tehnična dokumentacija za Technical product
izdelke documentation
SIST EN ISO 128-2:2020 en,fr,de

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

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SIST EN ISO 128-2:2020
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SIST EN ISO 128-2:2020
EN ISO 128-2
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2020
EUROPÄISCHE NORM
ICS 01.100.01 Supersedes EN ISO 128-20:2001, EN ISO 128-21:2001
English Version
Technical product documentation - General principles of
representation - Part 2: Basic conventions for lines (ISO
128-2:2020)

Documentation technique de produits - Principes Technische Produktdokumentation (TPD) - Allgemeine

généraux de représentation - Partie 2: Conventions de Grundlagen der Darstellung - Teil 2: Linien,

base pour les traits (ISO 128-2:2020) Grundregeln (ISO 128-2:2020)
This European Standard was approved by CEN on 2 July 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 128-2:2020 E

worldwide for CEN national Members.
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SIST EN ISO 128-2:2020
EN ISO 128-2:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 128-2:2020
EN ISO 128-2:2020 (E)
European foreword

This document (EN ISO 128-2:2020) has been prepared by Technical Committee ISO/TC 10 "Technical

product documentation" in collaboration with Technical Committee CEN/SS F01 “Technical drawings”

the secretariat of which is held by CCMC.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by February 2021, and conflicting national standards

shall be withdrawn at the latest by February 2021.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN ISO 128-20:2001 and EN ISO 128-21:2001.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,

Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of

North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO 128-2:2020 has been approved by CEN as EN ISO 128-2:2020 without any modification.

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SIST EN ISO 128-2:2020
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SIST EN ISO 128-2:2020
INTERNATIONAL ISO
STANDARD 128-2
First edition
2020-07
Technical product documentation
(TPD) — General principles of
representation —
Part 2:
Basic conventions for lines
Documentation technique de produits (TPD) — Principes généraux de
représentation —
Partie 2: Conventions de base pour les traits
Reference number
ISO 128-2:2020(E)
ISO 2020
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SIST EN ISO 128-2:2020
ISO 128-2:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

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: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
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SIST EN ISO 128-2:2020
ISO 128-2:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 2

4 Types of lines ............................................................................................................................................................................................................ 3

4.1 General ........................................................................................................................................................................................................... 3

4.2 Basic types .................................................................................................................................................................................................. 3

4.3 Line sub types .......................................................................................................................................................................................... 4

4.4 Variations of the basic types of lines .................................................................................................................................... 4

4.5 Combinations of lines with the same length ................................................................................................................. 4

4.5.1 Arrangement of two or more lines parallel to each other ............................................................ 4

4.5.2 Arrangement of two different types of lines ............................................................................................ 5

4.5.3 Arrangement of two continuous lines parallel to each other with regularly

recurring connecting elements between them ...................................................................................... 5

4.5.4 Arrangement of regularly recurring geometric pictorial elements in

association with continuous lines ..................................................................................................................... 5

5 Line dimensions .................................................................................................................................................................................................... 6

5.1 Line width ................................................................................................................................................................................................... 6

5.2 Deviation in line width ..................................................................................................................................................................... 6

5.3 Configuration of lines ........................................................................................................................................................................ 6

6 Draughting of lines ............................................................................................................................................................................................. 7

6.1 Spacing ........................................................................................................................................................................................................... 7

6.2 Junctions ....................................................................................................................................................................................................... 7

6.2.1 Types .......................................................................................................................................................................................... 7

6.2.2 Representation .................................................................................................................................................................. 9

6.3 Location of a second line .............................................................................................................................................................10

6.4 Hierarchy of overlapping lines ...............................................................................................................................................10

7 Colours .........................................................................................................................................................................................................................11

8 Designation .............................................................................................................................................................................................................11

9 Basic conventions and applications for leader lines and reference lines ..............................................11

9.1 Presentation of leader lines ......................................................................................................................................................11

9.2 Representation of reference lines ........................................................................................................................................14

9.3 Indication of instructions............................................................................................................................................................15

Annex A (informative) Preparation of lines by CAD systems ...................................................................................................17

Annex B (normative) Lines on construction technical drawings .........................................................................................30

Annex C (informative) Examples of application on construction technical drawings ...................................33

Annex D (normative) Types of lines and their application on mechanical engineering

technical drawings ...........................................................................................................................................................................................39

Annex E (informative) Examples of application on mechanical engineering technical drawings.....43

Annex F (normative) Types of lines and their application on shipbuilding technical drawings ........56

Annex G (informative) Application examples of the different types of lines on shipbuilding

technical drawings ...........................................................................................................................................................................................58

Bibliography .............................................................................................................................................................................................................................69

© ISO 2020 – All rights reserved iii
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SIST EN ISO 128-2:2020
ISO 128-2:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

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

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/

iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 10, Technical product documentation.

This first edition cancels and replaces the following documents:
— ISO 128-20:1996
— ISO 128-21:1997
— ISO 128-22:1999
— ISO 128-23:1999
— ISO 128-24:2014
— ISO 128-25:1999
The main changes to these documents are as follows:
— harmonization of the former parts listed above;
— introduction of the hierarchy of overlapping lines.
A list of all parts in the ISO 128 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.
iv © ISO 2020 – All rights reserved
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SIST EN ISO 128-2:2020
ISO 128-2:2020(E)
Introduction

ISO 128-2 contains generally applicable rules for the presentation of lines in all kinds of technical

product documentation.

All figures in this document have been drawn in first-angle projection. It should be understood that

third-angle projection or other methods could have been used equally well without prejudice to the

principles established.

The application of lines within drawings of special technical fields varies considerably. Therefore, rules

of application specific to technical fields are given in Annexes B to G.

Annex A provides information for the calculation of the most important basic types of non-continuous

lines according to types of lines and their line elements.
© ISO 2020 – All rights reserved v
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SIST EN ISO 128-2:2020
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SIST EN ISO 128-2:2020
INTERNATIONAL STANDARD ISO 128-2:2020(E)
Technical product documentation (TPD) — General
principles of representation —
Part 2:
Basic conventions for lines
1 Scope

This document establishes the types of lines used in technical drawings (e.g. diagrams, plans or

maps), their designations and their configurations, as well as general rules for the draughting of lines.

In addition, this document specifies general rules for the representation of leader and reference lines

and their components as well as for the arrangement of instructions on or at leader lines in technical

documents. Annexes have been provided for specific information on mechanical, construction and

shipbuilding technical drawings.

For the purposes of this document the term “technical drawing” is interpreted in the broadest

possible sense encompassing the total package of documentation specifying the product (workpiece,

subassembly, assembly).
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 128-3, Technical drawings — General principles of representation — Part 3: Views, sections and cuts

ISO 128-15, Technical product documentation (TPD) — General principles of presentation — Part 15:

Presentation of shipbuilding drawings

ISO 129-1, Technical product documentation (TPD) — Presentation of dimensions and tolerances — Part 1:

General principles

ISO 129-5, Technical product documentation (TPD) — Presentation of dimensions and tolerances — Part 5:

Dimensioning of structural metal work

ISO 1101, Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form,

orientation, location and run-out
ISO 2203, Technical drawings — Conventional representation of gears

ISO 2538-2, Geometrical product specifications (GPS) — Wedges — Part 2: Dimensioning and tolerancing

ISO 2553, Welding and allied processes — Symbolic representation on drawings — Welded joints

ISO 3040, Geometrical product specifications (GPS) — Dimensioning and tolerancing — Cones

ISO 3766, Construction drawings — Simplified representation of concrete reinforcement

ISO 4463-1, Measurement methods for building — Setting-out and measurement — Part 1: Planning and

organization, measuring procedures, acceptance criteria

ISO 4463-3, Measurement methods for building — Setting-out and measurement — Part 3: Check-lists for

the procurement of surveys and measurement services
© ISO 2020 – All rights reserved 1
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SIST EN ISO 128-2:2020
ISO 128-2:2020(E)

ISO 5261, Technical drawings — Simplified representation of bars and profile sections

ISO 5455, Technical drawings — Scales
ISO 5456-4, Technical drawings — Projection methods — Part 4: Central projection

ISO 5459, Geometrical product specifications (GPS) — Geometrical tolerancing — Datums and datum systems

ISO 6410-1, Technical drawings — Screw threads and threaded parts — Part 1: General conventions

ISO 6428, Technical drawings — Requirements for microcopying

ISO 7437, Technical drawings — Technical drawings — Construction drawings — General rules for

execution of production drawings for prefabricated structural components

ISO 7519, Technical drawings — Construction drawings — General principles of presentation for general

arrangement and assembly drawings

ISO 8560, Technical drawings — Construction drawings — Representation of modular sizes, lines and grids

ISO 10110-1, Optics and photonics — Preparation of drawings for optical elements and systems —

Part 1: General

ISO 10135, Geometrical product specifications (GPS) — Drawing indications for moulded parts in technical

product documentation (TPD)

ISO 10209, Technical product documentation — Vocabulary — Terms relating to technical drawings,

product definition and related documentation
ISO 11091, Construction drawings — Landscape drawing practice

ISO 12671, Thermal spraying — Thermally sprayed coatings — Symbolic representation on drawings

ISO 15785, Technical drawings — Symbolic presentation and indication of adhesive, fold and pressed joints

ISO 15787, Technical product documentation — Heat-treated ferrous parts — Presentation and indications

ISO 16792, Technical product documentation — Digital product definition data practices

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 10209 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
graphical basic element

continuous graphical object with rounded or squared end shape which is represented in any way (e.g.

straight, curved), which has a length and a width
Note 1 to entry: See Figure A.1.
3.2
dot
graphical basic element (3.1) having a length equal to the width, d
Note 1 to entry: See Figure A.2.
2 © ISO 2020 – All rights reserved
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SIST EN ISO 128-2:2020
ISO 128-2:2020(E)
3.3
line

set of one or more graphical basic elements (3.1) having a length of more than the width

Note 1 to entry: See Figure A.3.
3.4
technical drawing

drawing showing a technical installation, process or product with a view to clarifying its structure and

enabling its construction
[SOURCE: ISO 5127:2017, 3.4.7.54, modified — Note 1 to entry removed.]
4 Types of lines
4.1 General

The line type designation consists of a combination of a basic line type and a subtype, depending on the

line width, see 4.2.

For the purposes of this document a line type application number is used to number the application

examples for the line types.

For applying line types to construction technical drawings Annex B shall be applied. For applying line

types to mechanical engineering technical drawings Annex D shall be applied. For applying line types

to ship building technical drawings Annex F shall be applied.
4.2 Basic types
The basic line types are given in Table 1.
Table 1 — Basic line types
No. Representation Description
01 Continuous line
02 Dashed line
03 Dashed spaced line
04 Long-dashed dotted line
05 Long-dashed double-dotted line
06 Long-dashed triplicate-dotted line
07 Dotted line
08 Long-dashed short-dashed line
© ISO 2020 – All rights reserved 3
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SIST EN ISO 128-2:2020
ISO 128-2:2020(E)
Table 1 (continued)
No. Representation Description
Long-dashed double-short-dashed
line
10 Dashed dotted line
11 Double-dashed dotted line
12 Dashed double-dotted line
13 Double-dashed double-dotted line
14 Dashed triplicate-dotted line
15 Double-dashed triplicate-dotted line
4.3 Line sub types
The line sub types are given in Table 2.
Table 2 — Line sub types
Sub-type
Representation Description
no.
.1 Narrow
.2 Wide
.3 Extra wide
Line identification structure
4.4 Variations of the basic types of lines

The straight lines in Table 1 and the line widths of Table 2 can have variations as shown in Table 3.

Table 3 — Line variations
Representation Description
Uniform wavy continuous line
Uniform spiral continuous line
Uniform zigzag continuous line
Freehand / freeform curve continu-
ous line

NOTE Table 3 contains only variations of the basic type of line No. 01. Variations of the basic types of Nos. 02 to 15 are

possible and are presented in the same way.
4.5 Combinations of lines with the same length
4.5.1 Arrangement of two or more lines parallel to each other
For examples see Figure 1.
4 © ISO 2020 – All rights reserved
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SIST EN ISO 128-2:2020
ISO 128-2:2020(E)
Figure 1 — Example of lines parallel to each other
4.5.2 Arrangement of two different types of lines
a) With different line widths superimposed. See Figure 2 a) and b) for examples.

a) A continuous line and a dotted line b) A continuous line and a dashed spaced line

Figure 2 — Example of superimposed lines
b) Arranged next to each other. See Figure 3 for an example.
Figure 3 — Two continuous narrow lines either side of a wide dashed line

4.5.3 Arrangement of two continuous lines parallel to each other with regularly recurring

connecting elements between them
See Figure 4 a) and b) for examples.
a) Filled circular elements b) Filled trapezoidal elements

Figure 4 — Example of lines parallel to each other with regularly recurring connecting

elements

4.5.4 Arrangement of regularly recurring geometric pictorial elements in association with

continuous lines
a) Without interruption of a continuous line. See Figure 5 for examples.
Figure 5 — Without interruption of a continuous line
b) With interruption of a continuous line. See Figure 6 for examples.
© ISO 2020 – All rights reserved 5
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SIST EN ISO 128-2:2020
ISO 128-2:2020(E)
Figure 6 — With interruption of a continuous line
5 Line dimensions
5.1 Line width

The width, d, of all types of lines shall be one of the following depending on the type and size of the

technical drawing. This series is based on a common ratio 1: √2 (≈1:1,4).
0,13 mm; 0,18 mm; 0,25 mm; 0,35 mm; 0,5 mm; 0,7 mm; 1 mm; 1,4 mm; 2 mm.
The widths of extra wide, wide and narrow lines are in the ratio 4:2:1.
The line width of any one line shall be constant throughout the whole line.

See Annexes B, D and F for information on line widths pertaining to construction, mechanical and

shipbuilding technical drawings.
5.2 Deviation in line width

Line widths can deviate from those specified in 5.1 providing that it is possible to differentiate

unambiguously between two adjacent lines with different widths. If technical drawing equipment

which produces constant line width is used, the deviation in line width between two such lines shall not

be greater than ± 0,1d.
5.3 Configuration of lines

For the preparation of technical drawings, the lengths of line elements should conform to those of

Table 4.
Table 4 — Lengths of line elements
Drawing element Line type no. Length
04 to 07 and
Dot ≤ d
10 to 15
02 and
Gap 3d
04 to 15
Short dash 08 and 09 6d
02, 03 and
Dash 12d
10 to 15
04 to 06,
Long dash ≈24d
08 and 09
Space 03 18d

NOTE The lengths shown in this table are valid for line elements with semi-circular and

squared ends. In the case of line elements with semi-circular ends, the length of the line

element corresponds to the distance covered by a technical pen (with a tubular tip and

using India ink) from the origin up to the end of the line element. The total length of such

a line element is the sum of the length shown in this table, plus d.
6 © ISO 2020 – All rights reserved
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SIST EN ISO 128-2:2020
ISO 128-2:2020(E)

Formulae for the calculation of some of the basic types of lines and line elements are given in Annex A.

The formulae are intended to facilitate the preparation of technical drawings using computer-aided

design (CAD) systems.
6 Draughting of lines
6.1 Spacing
The minimum space between parallel lines should not be less than 0,7 mm.

In certain cases when computer-aided technical drawing techniques are used, the spacing of lines on

the technical drawing does not represent the actual spacing, for example for the representation of

screw threads. This has to be considered when data sets are established, for example for the operation

of machine tools.
6.2 Junctions
6.2.1 Types

The basic types of lines, nos. 02 to 06 and nos. 08 to 15, should meet at a dash to avoid ambiguity; see

Figures 7 to 12.
Figure 7 — Long-dashed short-dashed lines intersecting as a cross
Figure 8 — Dashed lines intersecting as a cross
© ISO 2020 – All rights reserved 7
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