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IS0
I NTE R N AT1 ON A L ORGAN I ZATlO N
FOR STA N DA RD I ZATl O N
IS0 RECOMMENDATION
O
R 128
ENGINEERING DRAWING
PRINCIPLES OF PRESENTATION
lrt EDITION
September 1959
O
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Copies to be obtained through the national standards organizations.
Also issued in French and Russian.
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BRIEF HISTORY
The IS0 Recommendation R 128, Engineering Drui~'in.q - Principles of' Presenta-
rion, was drawn up by Technical Committee ISO/TC IO, Drawings (General Principles),
the Secretariat of which is held by the Association Suisse de Normalisation (SNV).
During its first meeting, held in Zurich, in September 1951, the Technical Com-
mittee decided to use as the basis for its work the ISA Bulletin No. 32, drawn up by the
former International Federation of the National Standardizing Associations (ISA). The
development of the various drafts was entrusted to Sub-Committee SC I, Preli/ninary
work, comprising Austria, Belgium, France, Italy, Netherlands, Sweden, Switzerland,
United Kingdom and, since 1952, Germany.
After six meetings spaced over the years 1952, 1953 and 1954, the Sub-Committee
submitted to the Technical Committee a proposal dealing with thc principles of presen-
tation. At its second meeting held in Stockholm, in June 1955, thc Technical Committee
adopted this proposal as a Draft IS0 Recommendation.
On 31 December 1956, the Draft IS0 Recommendation was distributed to all the
IS0 Member Bodies and was approved, subject to a certain number of modifications,
by the following 19 (out of a total of 38) Member Bodies:
Australia *Greece Norway
*Brazil Israel Pakistan
Canada Italy Spain
Denmark Japan Sui tzerlsnd
Finland Mexico Turkey
France Netherlands U.S.S.R.
Germany
No Member Body opposed the approval of the Draft.
The Draft IS0 Recommendation was then submitted, by correspondence, to the
in September 1959, to accept it as an IS0 RECOMMENDATION.
Council, which decided,
The simplest possible figures have been chosen to illustrate the text. Some figures
are so clear that they need no comment. The explanatory texts allow these principles
to be adopted to those more complicated situations which arise in practice.
* These Member Bodies stated that they had no objection to the Draft being approved.
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ISO/R 121 . 1BS@ (E)
TABLE OF CONTENTS
pug0
Introductory Note . 4
1 . Views . 4
1.1 Designation of the views . 4
1.2 Relative position of views . 5
Method E (known as the European or First angle)
..... 5
Method A (known as the American or Third angle)
..... 5
1.3 Special views . 6
1.4 Choice of views . 6
2 . Lines . 7
3 . Sections . 8
3.1 Notes on hatching . 8
3.2 Thin sections . 9
3.3 Notes on sections . 9
3.4 Cutting planes (Examples) . 9
3.5 Revolved in place or removed sections . 10
3.6 Half sections . 11
3.î Local sections . 11
3.5 Disposition of successivc sections . 11
4 . Special cases . 12
4.1 Adjacent parts . 12
4.2 Intersections . 12
4.3 Representation of some plane faces . 12
Parts located in front of a cutting plane . 13
4.4
4.5 Partial views of symmetrical objects . 13
4.6 Interrupted views. . 13
5 . Simplified representation of threaded parts . 14
5.1 Visible screw threads . 14
5.2 Hidden screw threads . 14
5.3 Sections of threaded parts . 14
5.4 End view of screw threads . 14
5.5 Limits of useful length of screw threads . 14
5.6 Assembled threaded parts . 15
I
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'L 3 ., 180/R 128 - 1959 (E)
IS0 Recommendation
R 128
September 1959
ENGIN EERl N G DRAWING
PRINCIPLES OF PRESENTATION
INTRODUCTORY NOTE
For uniformity, all the dimensions in this IS0 Recommendation are given in
metric units only and the figures are in European (First angle) projection. It
should be understood that inch units and/or American (Third angle) projedtion
could equally well have been used without prejudice to the princi,ples established.
1. VIEWS
1.1 Designation of the views
View in direction A = View from the front
View in direction B = View from above
View in direction C = View from the left
,L A &
View in direction D = View from the right
View in direction E = View from :below
.
El
View in direction F = View from the rear
I Fig, 1
The front view (principal view) having been chosen, the other usual views
'
make with it and between themselves angIes of 90" or multiples of 90".
$1 $1 !
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ISO/R 128 - 1959 (E)
1.2 Relative position of views
Two methods exist :
Method E known as the European or First angle method (Fig. 2)
With reference to the front view the other views are arranged as follows:
The view from above is placed underneath
The view from below is placed above
The view from the left is placed on the right
The view from the right is placed on the left
The view from the rear may normally be placed on the left or on the
right, as may be found convenient.
The distinctive symbol of this method is shown in Figure 3.
O
a@
Fig. 3
Fig. 2
Mcthod A known as the American or Third angle method (Fig. 4)
With reference to the front view the other views are arranged as follows:
The view from above is placed above
The view from below is placed underneath
The view from the left is placed on the left
The view from the right is placed on the right
The view from the rear may normally be placed on the left or on the
right, as may be found convenient.
The distinctive symbol of this method is shown in Figure 5.
O
Fig. 5
Fig. 4
The method used is indicated on the drawing by means of its distinctive
symbol (Fig. 3 and 5).
This is placed clearly in a space provided for the purpose in the title block
of the drawing near the indication of the scale.
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ISO/R 128 - 1959 (E)
1.3 Sperial views
If a view is not drawn in one of the six directions defined above (Fig. 1,
page 4) or if the position of a view does not conform to the method
used for the drawing (Fig. 2 and 4, page 5), the direction of view
is shown by an arrow identified by a letter (Fig. 6 and 7).
'* View A
Fig. 6
Fig. 7
1.4 Clioiee OP views
view should generally show the part in the functioning
The front
position. Parts that can be used in any position, for instance screws or
bolts, etc., should generally be drawn in the main position of manufacture.
The number of views (including sections) should be limited to the minimum
necessary and sufficient to represent the object without ambiguity.
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*
ISO/R 128 - 1958 (E)
2. LINES
llefer to Flours 8 13xarnplerr 01 applloatlon
Type of llne
I
A I Continuous thick Visible outlines and edges
Fictitious outlines and edges
Dimension and leader lines
B Hatching
Outlines of adjacent parts
Continuous thin
Outlines of revolved sections
I I
I I
Limits of partial views or sections, if
the liiie is not an axis
...