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MEM09002B Interpret technical drawings
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MEM09002B Interpret technical drawing
Learning Resource
This publication is supplied with the understanding that the
authors, designers and editors are not responsible for the
results of any actions taken on the basis of information in
this work, nor for any errors or omissions; and the
publisher is not engaged in rendering legal, accounting,
engineering or other professional services. The publisher,
authors and designers disclaim all and any liability to any
person, whether a purchaser of this publication or not, in
respect of anything and of the consequences of anything
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reliance, whether whole or partial, upon the whole or any
part of the contents of this publication.
Acknowledgements
© 2017 TasTAFE
First published May 2015
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Table of Contents
1.
Select correct technical drawing ...................................................................... 6
Australian Standards ------------------------------------------------------------------------------- 8
1.1
Drawing is checked and validated against job requirements or equipment ................. 9
Drawing Layouts ----------------------------------------------------------------------------------- 9
Drawing Frame, Grid Line, Fold Lines and Camera Lines ---------------------------------- 10
Title Blocks ----------------------------------------------------------------------------------------- 11
Symbols Indicating 1st or 3rd Angle Projection ----------------------------------------------- 11
The Concept of 1ST and 3RD Angle Projection ----------------------------------------------- 11
1.2
Drawing version is checked and validated .......................................................................... 13
Drawing Numbering ------------------------------------------------------------------------------ 13
Activity 1-------------------------------------------------------------------------------------------- 14
Activity 2-------------------------------------------------------------------------------------------- 14
2.
Interpret technical drawing............................................................................. 15
2.1
Instructions are identified and followed as required ........................................................ 15
Line Type, Dimension and Line Groups ------------------------------------------------------- 15
Letters, Numerals and Symbols ----------------------------------------------------------------- 16
Projection Drawings ------------------------------------------------------------------------------ 16
2.2
Dimensions are identified as appropriate to field of employment ................................ 20
Dimensions ----------------------------------------------------------------------------------------- 20
Scale ------------------------------------------------------------------------------------------------- 20
Activity 3-------------------------------------------------------------------------------------------- 21
2.3
Symbols are recognised in the drawing as appropriate ................................................... 21
Abbreviations -------------------------------------------------------------------------------------- 22
Activity 4-------------------------------------------------------------------------------------------- 23
Activity 5-------------------------------------------------------------------------------------------- 23
2.4
Components, assemblies or objects are recognised as required .................................. 23
Sections --------------------------------------------------------------------------------------------- 23
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Tolerances ------------------------------------------------------------------------------------------ 24
Activity 6-------------------------------------------------------------------------------------------- 25
Datums ---------------------------------------------------------------------------------------------- 26
Activity 7-------------------------------------------------------------------------------------------- 27
2.5
Material requirements are identified as required .............................................................. 28
Activity 8-------------------------------------------------------------------------------------------- 28
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Select correct technical drawing
The Unit provides an introduction to the conventions that are used in engineering technical
drawings in Australia. This Unit will provide you with information enabling you to read and
interpret some of aspects of technical drawings.
The knowledge in this Unit will also help in the process of producing your own technical
drawings, however it is not the role of this Unit to teach you how to create technical
drawings. A range of other Units in this series will provide that knowledge, for example,
‘MEM30032A Produce basic engineering drawings‘, and ‘MEM30031A Operate CAD systems
to produce basic drawing elements’.
As the image below illustrates, technical drawings play a vital role in the process of
transforming designs into objects. Technical drawings are used to communicate designs
created by engineers, to those who will manufacture or construct those designs. The image
is taken from the Australian company, PPM Project Management’s website.
Figure 1 Drawings play a vital role in engineering projects
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Engineering and construction projects may involve substantial sums of money in the case of
the construction of a highway, a port or a large public building for example, and almost
always relatively substantial sums of money from the client’s point of view.
The requirements described in technical drawings form important ‘terms’ within a legal
contract. The drafter’s role in design and manufacture or construction is an important one!
Given the complexity of construction and manufacturing tasks, the range of people and the
sums of money involved - there is great potential for mistakes, confusion, delays, conflicts,
cost over-runs, financial losses and even court cases.
Therefore, it is vital that a common visual language exist for technical drawing and that that
is used by all involved in the process. This language must be learned by new comers. With
a common drawing language everyone may share the same understanding of a design.
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Australian Standards
For the reasons noted above, requirements for technical drawings are described in
Australian Standards. In this Unit we will look at the ‘AS 1100.101-1992 Technical drawing General principles’ in some detail. We will introduce you to the stylistic requirements for
technical drawing and the meaning of many of the visual elements throughout this Unit.
Although the Standard dates back to 1992 it has been in existence in various forms for many
years prior to that. The latest version at the time of writing, was the 1992 version
‘reconfirmed’ for 2014. Take care that you always work from the latest current version of
Standards.
The Standard is a document you will refer to continually throughout your career, rather
than a book you read once as a student.
AS 1100.101 is actually a part of one large set of Standards dealing with technical drawing,
the other Standards documents in relation to drawing which may become relevant to you in
your work are:

AS 1100.201: Mechanical drawing

AS 1100.301: Architectural drawing

AS 1100.401: Engineering survey and engineering survey design drawing

AS 1100.501: Structural engineering drawing
Australian Standards are used to specify detailed advice relevant to a vast range of products
and services. Strictly speaking, Standards are not law, unless ‘called up’ by mention in
legislation. So Standards may not always be legally required to be followed. However,
because of the risks described above, most businesses and government organisations will
choose to use Australian Standard methods always, so as to reduce legal, financial and safety
risks. Your employers may require you to use Standards and all local governments and
other development control agencies are likely to require you to use the Standard methods,
exclusively.
Some Australian laws are freely available from your state government website. Better still,
the http://www.austlii.edu.au/ website provided by the faculties of law at the University of
Technology Sydney and the University of NSW Australian list all Australian law in one online
location with free access.
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Unlike laws, Australian Standards
are owned by a company called SAI
Global, and any Standards must be
purchased to use.
For more
Figure 2 SAI Global owns Australian
information on Standards visit the
Standards
SAI
Global
website
http://www.saiglobal.com/.
City
branch state libraries and educational facilities may have online subscriptions to enable free
viewing of some or all of the Australian Standards.
Students will need access to the latest version of AS1100.101 to work through this Unit.
Refer to the contents page of the AS1100.101 now, note the general structure of the
Standard document so that you can navigate your way to the information you require to
complete the Activities in this Unit.
Note that the first subsections of each Section of the Standard, such as the subsections
Scope or Terminology, will give you valuable information like definitions and examples of
applications.
The Table of Abbreviations and Appendices sections contain similar
information that is also important to know. There are also pieces of important information
throughout the Standard. Be prepared to spend time ranging over the Standard document
using the Contents Page and Index at the end, to find information quickly.
Also note the Standard is quite a proscriptive document, with relatively little opportunity for
personal choice. Where options are available in the Standard some of these will be noted
briefly.
1.1
Drawing is checked and validated against job requirements or equipment
In this section we will look first at the basics of paper type and size, ‘drawing frames’ and
layouts, as well as fold and ‘trimming lines’, ‘title blocks’ and some of the symbols used.
In the following chapter we will look at other aspects of drawing such as ‘scale’, dimensions,
and symbols used to indicate the way the drawings are arranged for the viewer.
As you read through the introduction given to each topic in this Unit, please also carefully
read the detailed information on that topic in the Standard for the full explanation.
Drawing Layouts
The Standard describes drawing layouts in Section 2. The Standard prescribes the type of
paper materials, the size designations of sheets e.g. ‘A2’, and the cut sheet dimensions e.g.
420 x 594 mm, that are used for standard or wider sheets. There are sheet sizes that are
referred to as ‘preferred’ by the Standard, and there other ‘non-preferred’ options too.
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The illustration in Figure 3 over the page, shows one of the typical drawing layouts the
Standard describes. The illustrations used in this Unit are taken from the Standard.
Unfortunately and ironically, the line work in illustrations in the Standard have degraded
(presumably through copying) to a very poor quality. The illustrations in the Standard have
been ‘touched up’ to make lines clearly visible in this learning resource. Note that this
means line thickness is altered and may not be representative of the required line
thicknesses described in the Standard.
Also note how copying and printing from a hard copy drawing, can degrade image quality.
Being able to print an original quality drawing from a CAD programs preserves original
drawing quality.
Drawing Frame, Grid Line, Fold Lines and Camera Lines
Referring to Figure 3 over the page, note the frame around the blank drawing space. Also
note how the frame is drawn within the edge of the drawing sheet.
Note that the frame can also act as a grid with coordinates. You can see for e.g. that the A1
grid positon is located at the top left position of the drawing frame. Grid references can be
used to help identify the location of a detail in a large drawing with a co-worker or client.
Figure 3
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The Standard discusses how ‘Fold Lines’ for hard copy large sheets should be indicated, and
also how ‘Camera Lines’ should be indicated. Read the relevant subsections of the Standard
on these topics.
Title Blocks
Note the presence of a Title Block (bottom right Figure 3). Other tables of information can
be included, called ‘Parts Lists’ and ‘Materials Lists’. Read the text and look at the images in
the Standard to learn what types of layouts, blocks and lists may be relevant to the type of
work you will be doing.
The Standard describes options for arrangements of the Title Block and lists, along the
bottom or the top of the frame, instead of the method shown in the illustration above.
Placement of blocks is an area where the Standard allows flexibility to suit the drawing.
The layout system for the Title Blocks of a drawing can be chosen from the options in the
Standard, to enable the object you are drawing to fit well within the blank drawing space,
being centrally positioned and as large as possible while fitting within the space available.
The Standard specifies the exact dimensions of the Title Block in mm. for drawing sheet
sizes from AO to A4.
Symbols Indicating 1st or 3rd Angle Projection
Two symbols are always used on drawings sheets to indicate whether you are viewing a
drawing which presents the views of the object, in either ‘1st’ or ‘3rd Angle Projection’.
Figure 4
1ST Angle and 3RD Angle Projection Symbol
The symbol on the left in Figure 4 indicates a 1ST Angle Projection and the symbol on the
right shows a 3RD Angle Projection.
When you see the Australian Standard symbols for 1ST and 3RD Angle Projection on a
drawing, they indicate how the different views (plans and elevations) are connected and
orientated on the drawing sheet.
The Concept of 1ST and 3RD Angle Projection
1ST and 3RD Angle Projection is a method of showing two dimensional views, and is used in
engineering drawings extensively.
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To explain what 1ST and 3RD Angle Projection are we will use a series of images to describe
this concept which some may find initially challenging and counterintuitive.
Imagine we want to draw the two dimensional ‘plan’ and ‘elevation’ views, of a three
dimensional object (as pictured in the centre of the left image in Figure 5). And we want to
draw that object on to the two dimensional surfaces of an imaginary paper box around our
object. (Ignore the arrows and line drawings in the image they will distract you from our
explanation).
Figure 5
Drawings Arranged in 1ST Angle Projection
We have choices as to which way we ‘unfold the box’. The choices we make will alter what
arrangement of drawn objects we would see when the box was folded open completely flat,
as shown in the image in the right of Figure 5.
If we ‘unfolded’ box as shown by the illustration in the centre of Figure 5, we are working in
1ST Angle Projection.
Figure 6
Drawings arrange in 3RD Angle Projection
If we unfold the box as shown by the illustration in the centre of Figure 6, we are working in
3RD Angle Projection.
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Do not confuse 1ST and 3RD Angle Projection, with ‘Projection Drawings’. 1ST and 3RD Angle
Projection are merely methods of arranging two dimensional drawn views of an object
within the drawing frame. Projection Drawings on the other hand are three dimensional like
drawings, that can be created from simple two dimensional views, like the plans or
elevations shown in the right of both Figure 5 and 6 above. We will discuss the type of
Projection Drawings the Standard enables you to use in the next chapter.
1.2
Drawing version is checked and validated
The nature of the design and manufacturing or construction processes often means changes
are made to designs as the project progresses and comes to fruition in the real world. The
changes will almost always need to be negotiated within a contract framework among
stakeholders including clients, project managers and engineers.
You will note that the technical draftsperson does not exist on this list. If there are changes
to be made you will be instructed by those responsible for making those decisions as to the
work to be done. Do not confuse changing a drawing, with changing the design. Changing
the design is not the drafter’s role. The drafter’s role is to illustrate the design.
Drawing Numbering
Changes made to drawings must be noted and recorded for all stakeholders to see in a very
clear and systematic manner. Trades people working from an older or newer set of plans
can cause chaos, conflict, financial losses and lead to court cases. To avoid or minimise this
situation drawings must be carefully numbered.
The Standard requires that the Title Block will have a title/name of drawing, date, and names
of people/companies involved, and a ‘Drawing Number’.
The Standard says the Drawing Number should be located close to the right corner of a
Title Block that is located in the right corner. Alternatively the drawing may also have the
Drawing Number exhibited on other corners/sides as well, so that the Drawing Number is
visible when hard copy sheets are filed.
The Standard requires that Drawing Numbers be used, and where they should be located
but does not describe an appropriate numbering system. Your workplace may have a
comprehensive numbering system for drawings, which helps identify different jobs, multiple
drawings for a job, and crucially, the version or revision number of a drawing. Take for
example, the string of numbers below,
21-3-1.4-V2
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These numbers could be used to indicate client 21, project 3 for that client, drawing 1.4 for
that job, and version 2 of that drawing.
The Standard recommends that space be provided to the left of the Title Block to record
Supplementary Information. A Supplementary Information box can include reference to
drawing numbers, issues numbers and revision information.
Activity 1
With reference to the subsection number and title of AS1100.101, in your own words,
explain what the following terms mean and summarise what the Standard requires in
relation to:

‘Arrangement drawing’

‘Print trimming line’
Activity 2
Research the drawing numbering system used by one or more drafting offices.
After that process, describe in detail, a system of drawing naming and numbering that would
satisfy the following needs.

Your system must be AS1100.101compliant and you must note how it meets
relevant requirements of the Standard in your own words. (Be sure and refer to the
subsection number and name of the Standard).

Your system must clearly cover the identification of the drawing, version number
and any other information you think is required. Explain why you think it is required with
reference to the Standard or other information.
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Interpret technical drawing
In this chapter we will look at more drawing elements and information from the Standard, in
order to enable you to read and interpret a finished technical drawing.
In the first section of this chapter we will look briefly at the basic requirements of the
Standard for ‘line types’ and dimensions, letters and numerals.
We will also include an overview of the different types of ‘Projection Drawings’ the Standard
specifies in first section of this chapter.
In the latter parts of this chapter we will look at requirements for ‘scales’ and ‘dimensions’;
look at a large range of required ‘symbols’ and abbreviations; and the requirements for
showing ‘sections’ and ‘tolerances’ in engineering drawings.
Again, read the detailed information in Standard each time we introduce a new topic in this
chapter.
2.1
Instructions are identified and followed as required
The Standard provides instructions as to what line types, and what letters and numerals
must be used. In this section we will look at line types, dimensions and ‘line groups’.
We will also look at requirements for letters, numbers and symbols; followed by ‘projection
drawings’ and the identification of views of objects.
Line Type, Dimension and Line Groups
In AS1100.101 ‘Section 3 Lines’ describes requirements for ‘Types of Lines’. Read over
Section 3 now and pay particular attention to the information in ‘Table 3.1 Lines and
Applications’. Make sure you understand the terms like:

‘visible outlines’

‘fictitious outlines’

’break lines’

and what role a ‘chain’ performs, in providing dimensions in a drawing
Table 3.1 of the Standard provides examples of each of these in various illustrations. Be
sure you can find and recognise examples of each type of line in the examples.
The Standard also specifies the ‘dimensions’ or thickness of lines that must be used in ‘Figure
3.1 Line Groups’. Different thicknesses tell the viewer what information the line indicates.
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For example a ‘visible outline’ of an existing building is shown by a continuous, relatively
thick line, designated as an ‘A’ type line in Table 3.1 of the Standard.
Four ‘Line Groups’ are available to use. Note how the Line Groups use either: 0.35, 0.5, 0.7
or 1.0 mmm thickness for the ‘A’ type lines. The subordinate line types always have smaller
dimensions, i.e. they are thinner than the thicker ‘A’ type line in the Line Group.
You must select and use only one Line Group per drawing/drawing set.
Letters, Numerals and Symbols
‘Section 4 Letters, Numerals and Symbols’ of the Standard, specifies that characters (i.e.
letters, numbers and symbols) - whether drawn by hand or by CAD - should be of certain
heights as described in ‘Table 4.1’ of the Standard.
Note the requirements for spacing between characters and words. Note the increased
height requirement when using upper and lower case lettering. Note also the requirements
if stencilling hand drawn letters.
The Standard requires that the 0 be placed in front of all decimal fractions, e.g. ‘0.1mm’ not
‘.1mm’. Note the requirements for ‘Item’ referencing on a drawing. Note also the
requirements for general use symbols (e.g. ‘%’ or ‘&’) and terminators (e.g. full stops,
commas, colons).
Projection Drawings
The Standard allows for a range of Projection Drawing types, described in ‘Section 6
Projections’. Projection Drawings are drawings created by projecting lines back into space,
to indicate depth and to give the illusion that an object has three dimensions in a drawing.
Table 1 below, is taken from the Standard and shows what type of Projection Drawings can
be used.
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Table 1
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AS1100.101 Compliant Methods of Projection
Choices can be made from the Projection Drawing options listed in the Standard. Choices
should be made in order to best show the finished object in a three dimensional or three
dimensional like view.
Your engineer may wish to make these choices relative to the project team, or client’s
needs, but you may also be involved in making the choice. CAD technology may make
generating various Projection Drawings much faster and easier than manual drafting.
‘Axonometric’ and ‘Perspective’ projection drawings
often give good enough results in terms of conveying
what an object will look like in reality.
In Axonometric drawings, lines of the horizontal axis
of objects extend in parallel and do not meet. This
makes axonometric projections suitable for
presentation of objects that are small in real life.
Perspective projections use a number of vanishing
points to convey the convergence parallel lines we
witness in reality, when we look at a large object in
space. This makes perspective projections most
suitable for illustrating objects that are large in real life.
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Isometric means ‘having equal angles’ in Latin. An Isometric projection is a type of
Axonometric projection. The term Isometric is used to describe a projection which has a
central vertical perpendicular (90o) axis, with the horizontal edges of the object drawn at
angle (often at a 30°) to the viewer. All lines are drawn to the same scale in an Isometric
projection and the result drawing achieves a good balance of simplicity and the illusion of
three dimensions. For small objects the human eye will not perceive much distortion, with
large objects such as a building however, distortion is experienced.
Oblique means slanting or ‘at an angle to’ in
Latin. The term is used to designate a
method of projection where an elevation is
taken and parallel lines are projected back,
often at 45o. Note that dimensions of the
projected elements are transformed to a
reduced scale, often half scale – this gives
some illusion of ‘foreshortening’ a
phenomenon the human eye experiences as
parallel lines appear to converge as they head
into the distance. Note in the image, how an
oblique projection gives the impression that
the back of the cube is larger than the front
of the cube. This is viewed as a distortion of
reality because the eye is expecting to see
foreshortening occurring on the back of
cube.
The distortion appears to be
exaggerated partly because the depth of the
cube’s depth has been distorted to aid with
some illusion of 3D like fore-shortening.
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Perspective projections create more of
an illusion of three dimensions in a
drawing. There may be up to 4 ‘vanishing
points’ necessary to create the strongest
illusion of three dimensions in a drawing.
Our illustration contains only two but you
can easily imagine that with a tall building,
the parallel lines appear to slope toward a
point in the sky, and that deep foundations
for the building would do the same. The
Standard only allows 1, 2 and 3 point perspectives.
Identification of Views
The Standard also requires that the views of
surfaces objects depicted in projection drawings be
labelled with letters in a prescribed way.
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Dimensions are identified as appropriate to field of employment
‘Dimensions’ are the measurements of length or angle or other measurements that are
indicated on drawings. Dimensions are perhaps the most important function of drawings as
they provide information necessary for manufacture and construction. In this chapter we
will look at dimensions and scale in technical drawings.
Dimensions
In the Standard ‘Section 8 Dimensioning’ lists requirements for dimensions in drawings.
Read over Section 8.1 and 8.2 of the Standard now.
Note the subsections on ‘Fundamental rules’ for dimensions and the applications of
dimensioning symbols in Table 8.1. We will look at these symbols a little later in this
chapter, so instead focus on how dimensions may or must be arranged on drawings.
Note also the special requirements for providing dimensions for various forms and features
of an object. These features could include: ‘tapers’, ‘countersinks’, ‘chamfers’ and ‘arc
lengths’ for example.
Make sure you look at all the requirements and drawing examples in Sections 8.1 and 8.2 of
the Standard. Pay particular attention to those that you are likely to use regularly in your
work.
Scale
Scaling is used to enable maps and drawings to show large objects on relatively small drawing
surfaces or to show relatively small objects in greater detail.
The scale of a drawing is important to telling the viewer what is depicted, as illustrated in
this carton drawn by Roger Penwill taken from the Cadalyst company website.
Scales which reduce the drawn object relative to the actual object, are called ‘reduction
scales’. The scale below is a reduction scale.
SCALE 1:100
Scaling is also used to show relatively small objects at
a larger than life size, these are called ‘enlargement
scales’. The scale below is an enlargement scale.
SCALE 50:1
‘Section
5
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AS1100.101
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requirements for showing scale in drawings. Read over Section 5 now.
Note the subsections on how to indicate a scale, and the types of scale ratios that may be
used in different applications like engineering and architecture, and in surveying and mapping.
Activity 3
Referencing AS1100.101, how many methods of indicating scale are permitted? What are
the names of those scales?
Draw an example of a ‘graduate scale’, and submit that.
What do the terms ‘DO NOT SCALE ‘ and ‘NOT TO SCALE’ mean and what implications
do each have on drawings?
2.3
Symbols are recognised in the drawing as appropriate
We have discussed the requirements for the heights of symbols earlier in this chapter. The
Table below shows the symbols used to indicate what type of dimensions are being supplied
on a drawing.
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Diameter
Radius
Width of flats on square section
Tapers and their direction
Slope and direction
Centre-line
Diameter of a spherical surface
Radius of a spherical surface
Countersink
Counterbore or spotface
Depth of a feature
Arc length
Table 2
Symbols
Abbreviations
The Standard lists the abbreviations that must be used on drawings, to indicate a material,
form or other information. Read over Section 1.4 of the Standard now.
Table 1.1 lists abbreviations, both by the word to be abbreviated, and then by the abbreviation
(acronym). This means you can search for the abbreviation or full word, to create or
decipher the abbreviations. Note the types of information for which abbreviations are used
and if there are terms in there you do not understand, research those.
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Activity 4
Referencing the AS1100.101, what size and what shape object parts, are illustrated in the
drawing below?
Activity 5
Referencing the AS1100.101, what is the accepted abbreviation for the material ‘hardwood’?
Referencing the AS1100.101, what does the abbreviation ‘AGGR’ mean?
2.4
Components, assemblies or objects are recognised as required
To construct or manufacture an object requires the assembly of component parts. For
example, when constructing a house timber would be used to make a wall frame that might
be fixed to a slab of concrete and so on. It is necessary to show this information in
drawings.
We have discussed how abbreviations are used to indicate information on materials like
concrete or aggregate, and also components like pumps or pipes.
In this section we will discuss ‘sections’, ‘tolerances’ and ‘datums’ and the role these play in
illustrating ‘components’ and ‘assemblies’ in technical drawings.
Sections
‘Sections’ show a slice through an object and are a useful way to show details of complicated
objects, components and assemblies. The example in the Figure below is taken from the
Standard.
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Figure 7
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Section
Section 7 describes the requirements for sections in technical drawing, read over Section 7
now. Note how ‘hatching’ is used to indicate any surfaces cut by the section through the
object. Hatching refers to the shading effect produced by making diagonal parallel lines.
Note also the requirements for ‘local or part sections’ in the Standard.
Tolerances
When we manufacture or construct something, we must put component parts and natural
materials together; sometimes these also have to be physically fit into the natural
environment or built using natural materials which have some variations in size. Whether
we are fitting together engineered parts, or some combination of parts with natural
materials, engineers will specify ‘tolerances’ within which dimensions must fall, if the parts
are to fit together and work as intended.
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The example in the Figure below is taken from the Standard, and shows three methods of
presenting tolerances for linear dimensions on five examples.
Figure 8
Tolerance of Linear Dimensions
The Standard describes requirements for presenting tolerances in drawings in Section 8.3
‘General Tolerances and Related Principles’. Briefly read over that section now. This is a
relatively large Section of the Standard so note the example drawings most relevant to your
work area as a priority.
Activity 6
Referencing the AS1100.101, what type of section is shown in the illustration below?
From the information supplied, what type of object does the drawing show, and what
features does it have?
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The table below shows the symbols used to indicate different types of tolerances in
drawings.
Table 3
Symbols to Indicate Tolerance Types
Datums
A datum is a reference point for dimensions to be located/extend from. Examples of
datum’s include ground levels, sea level or some simple feature in the landscape like the top
of a wall or manhole cover or a feature within the design itself.
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Note the information on ‘datums’ in Section 8.3 and in Appendix H of the Standard.
Activity 7
Referencing the AS1100.101, what dimensions or other information, are indicated in the
illustration, about slope, tolerance and datum?
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2.5
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Material requirements are identified as required
Where several parts or materials are shown on the one drawing, the Standard requires that
a Parts List or Materials List table be included, either adjacent to or above the Title Block, or
on a separate sheet.
Refer back to Figure 3 in chapter 1 of this Unit, for an example of a drawing layout with a
Materials List, and also consult the examples provide in the Standard at Fig 2.6 through to
2.11 inclusive. The quality of illustrations in the Standard makes it difficult to determine the
exact requirements for Materials Lists visually. So, read Section ‘2.5.11 Material or parts list’
of the Standard to clarify requirements textually. You will note that there is some flexibility
however in relation to a Materials List, the Standard would require you to create a table that
included:

name of the part/material

type material

specification of that material’s required qualities

quantity of the part/material

drawing number of any detail drawing that may be relevant

a reference number to identify the material/part from any store room or suppliers
We discussed the role of abbreviations in the Standard in earlier in this chapter. Note that
abbreviations are also used to indicate material type on a drawing.
An Engineer may specify materials such as steel sheet or steel reinforcing for concrete or
aggregate for use as road base or in concrete. Each material will be chosen from a range of
available products, because it will best fulfil a specific role at a price. The specification of
materials is a design decision, i.e. it is one made by the Engineer not the Drafter. Supplier’s
websites/catalogues can be used to select and products for use. These publications contain
information on the way the materials will perform or what uses they are rated for.
To complete the last Activity for this Unit refer back to the section in chapter 1 on Title
Blocks and Lists, as well relevant sections in the Standard.
Activity 8
Create a hypothetical Title Block as a table in a word processing program or freehand.
Make your Title Block conform to the requirements of the Standard. For this Activity it is
OK to use approximate dimensions for the Title Block.
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MEM09002B Interpret technical drawing
Learning Resource
Note which paper sheet size your hypothetical Title Black would be drawn on, in a separate
statement below your Title Block.
Fill in all the fields of the Title Block with hypothetical information. Pay particular attention
to drawing number, scale, and miscellaneous information like sheet numbers or modification
numbers.
Provide some text below your title block explaining what the Standard requires.
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