Engineering drawing third edition

Line thicknesses 6Sizes of drawing paper 6 Preferred sheet series 6Non-preferred sheet series 6Rolls 6 Layouts of drawing sheets 8 Sheet frames borderlines 8 Dimensions not to scale 14 D

A.W Boundy

Ass Dip Mech Eng., M Phi/.,

M.I.IE Aust., M.I.IE U.S.A.

Associate Dean (Resources)

School of Engmeering

Darling Downs Institute of Advanced Education

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Line thicknesses 6

Sizes of drawing paper 6

Preferred sheet series 6Non-preferred sheet series 6Rolls 6

Layouts of drawing sheets 8

Sheet frames (borderlines) 8

Dimensions not to scale 14

Dimensions not complete 15

Dimensioning drawing features 15

Tapers 20

Screw threads 21

General representation 21Threads on assembly and specialthreads 21

Designation of threadedmembers 22

Dimensioning full and runoutthreads in holes 23

The ISO metric thread 23

Graphical comparison of metricthread series 24

Tapping size and clearance holesfor ISO metric threads 24

Sectioning-symbols and methods 26

General symbol 26Sectioning lines (cross-hatching) 26

Adjacent parts 26Dimensions 26Large areas 27Section cutting plane:

Application 27Sectioning thin areas 27Exceptions to the general rule 28Interposed and revolved

sections 28Removed sections 28Part or local sections 28Aligned sections 28

Drawing sectional views 29

The full sectional view 29The offset sectional view 30The half sectional view 30Rules to remember whensectioning 31

v

Welding standards 31Welding terminology 31Basic symbols 32Standard welding symbol 32Application of the standard weldingsymbol 33

Welding procedures 33Joint preparation 33

Indication on drawings 38Surface texture terminology 38Surface roughness

The standard symbol 39

Surface roughness (Ra)

applications 39Application of surface finish symbol

to drawings 39Roughness grade numbers 39Direction of surface pattern orlay 39

Introduction 47Shaft 47Hole 47Basic size 47Limits of size 48Deviation 48Tolerance 48

Allowance 49Grades of tolerance 49Bilateral limits 49Unilateral limits 49Fundamental deviation oftolerance 49

The hole-basis system 50The shaft-basis system 50Designation of a fit 50Application of tolerances todimensions 54

Methods of dimensioning to avoidaccumulation of tolerances 56

Introduction 56Types of assemblies 57Components assembledexternally 57Components assembledinternally 57

Profiles 65Angularity 65Concentricity 65Symmetry 65Runout 66

Chapter 2 Geometrical

constructions 83

The ellipse 107The parabola 110

Cycloids, involute, spirals,curves 113

Helixes 113

Cams 114Conic sections 116

Construction of geometrical shapes

and templates 117

Chapter 3 Orthogonal projection: First

and third angle 121

Introduction 122Principles of projection 122

Third-angle projection 122

Designation of third-angleviews 122

Number of views 124Projection of orthogonalviews 124

Primary auxiliary views 157

Types of primary auxiliaryviews 157

Partial auxiliary views 157Orientation of auxilia~y views 157

Secondary auxiliary views 161

Procedure 161Use of a secondary auxiliary view

to construct normal views 161

General rules 161

Problems 163

OJapter 5 Pictorial drawing: Isometric

and oblique parallel

method 179Isometric circles-four-centremethod 179

Isometric curves 179Isometric angles and non-isometriclines 179

Making an isometric drawing 182 Representation of details common

to pictorial drawings 183

Fillets and rounds 183Threads 183

Sectioning 183Dimensioning 183

Oblique parallel projection 184

Length of depth lines 184Circles on the oblique face 185Angles on oblique drawings 185Selection of the receding axis 186

Problems 187

assembly drawing 195

Detail drawings 196 Assembly drawings 196 Working drawings 198 Problems (working drawings) 198

Sample analysis 222 Problems 225

Chapter 8 Intersections and

development of surfaces 233

Development of prisms 234

Rectangular right prism 234Truncated right prism 234Rectangular prism pipe elbow 234Hexagonal right prism 236

Truncated hexagonal rightprism 236

Truncated oblique hexagonalprism 236

Other prismatic shapes 236

True length and inclination of lines 238

Methods of determining truelength 238

vii

Line of intersection-cylinders and

cones 242

1 Element method 242

2 Cutting plane method 242

3 Common sphere method 242

Development of breeches or Y pieces 270

Breeches piece-equal angle,equal diameters; unequal angle,equal diameters 270

Breeches piece-cylinder and twocones, equal angle 270

Development of transition pieces 274

Round-to-round transitionpiece 274

Square-to-round transitionpiece 276

Oblique hood 278Offset rectangle-to-rectangletransition piece 280

Problems (development) 282

This book has been written for students of Engineering

Drawing Two features of the book will, I hope, make the

subject easier tounderstand and use of the text beneficial.

First, lengthy explanatory detail has been reduced to

a minimum, with the step-by-step method of instruction

being used wherever possible.

Second, the problem format is that of examination

questions, giving the student essential-practice in this

approach.

Emphasis has been placed on providing a large

number and wide variety of problems for the various topics

dealt with Therefore, a complete instructional and

practical syllabus can be prepared to a content depth

consistent with prescribed course objectives.

Preface

Several reference tables commonly used by drafters have been included so that students may gain knowledge and practice in their use when solving the problems The tables, along with other information, make the book a

valuable reference for practising drafters and engineers The third edition has been revised throughout to

conform to current Australian Standards Some sections have been expanded, and two new topics-Geometry tolerancing and Computer-aided design and drafting/ Computer-aided manufacture-have been added because

of their increasing importance in modern technology.

Introductory and standards information

Engineering drawing is the main method of communi- The Standards Association of Australia has cation between all persons concerned with the recommended standards for drawing practice in all design and manufacture of components; the building fields of engineering, and these are set out in their and construction of works; and engineering projects publications Australian Standards (AS) 1100 Parts required by management or professional engineering 101 and 201.

staff.

This section presents the standards which are The practice of drawing is in many ways so relevant to mechanical drawing, and provides other repetitive that, in the interests of efficient introductory information that is often required by communication, it is necessary to standardise drafters and students.

methods to ensure the desired interpretation.

Standard abbreviations

The abbreviations in Table 1.1 have been selected Part 101, and are those which are commonly used from the more comprehensive list found in AS 1100 on mechanical engineering drawings.

Table 1.1 Standard abbreviations

E

galvanised-iron pipe GIP

computer-aided manufacture CAM

M

2

Term Abbreviation Term

raised countersunk head RSD CSK HD universal column UC

rectangular hollow section RHS V

VERT

regardless of feature size RFS volume

VOL

3

Types of line 2 The dimension, projection, cross-hatching and

The types of line which are commonly used in leader line, type 8, is illustrated Leader lines

engineering drawings are illustrated in Table 1.2 are of two types, one which terminates withFigure 1.1 includes examples of the use of nine an arrowhead at an outline and the other whichtypes of lines, lettered to correspond with the types terminates in a dot (4) within the outline of the

above (with the exception of type F). part to which it refers Leaders should be

1 The visible outline of the bracket, type A, is nearly at right angles to any line or surface.heavy and dark enough to make it stand out Further uses of type 8 lines are to partly outlineclearly on the drawing sheet This line should the adjacent part to which the bracket is bolted

be of even thickness and darkness and to represent fictitious outlines such as

HALF SECTION x-x FRONT VIEW

Fig 1.1 Use of different types of line

minor diameters of male threads and major In the case of the removed section, Y-Y,diameters of female threads (the latter are not which merely shows the cross-sectional shape

3 The short break line, type C, is drawn freehand the view is taken from, and the arrows may be

to terminate part views and sections as shown left off the cutting plane

It is also used to sketch the curved break 8 Surfaces requiring special treatment such as

section used on cylindrical members heat treatment or surface finish may be

4 A ruled zigzag line, type 0, is used for long indicated with a type J line drawn parallel tobreak lines which extend a short distance the profile of the surface in question

beyond the outlines on which they terminate 9 When drawing a component where it is

5 The hidden outline line, type E, represents necessary to show its relationship to aninternal features which cannot normally be adjacent part, the latter is outlined using a type

A hidden outline should commence with a indicate extreme positions of movable parts,dash (1) except where it is a continuation of and to outline tooling profiles in relation to work

a visible outline (2), where there is a space first set up in machine tools

Corners and junctions (3) should be formed by

dashes

6 The centre line, type G, denotes the axis of 5 I

symmetrical views as well as the axis and ca es

centre lines of holes Centre lines project a The scales recommended for use with the metricshort distance past the outline When produced system are:

further for use as dimension lines, they may Full size 1:1

revert to thin continuous (type B) lines Type Enlargement 2:1, 5:1, 10:1

G lines may also be used to show the outline Reduction 1:2, 1:2.5, 1:5, 1:10

of material which has to be removed (not

shown)

7 The cutting plane of the section, X-X, is Use of scales

represented by the type H line Arrows are Engineering drawings may be prepared full size,located at right angles to the thick ends of the enlarged or reduced in size Whatever size of scaleline, and point to the direction in which the is used, it is important that it be noted in or near thesectional view is being taken title block

S

Indication of scales Sizes of drawing paper

When more than one scale is used, they should be Preferred sheet series

shown close to the view(s) to which they refer and The Standards Association of Australia has

a note in the title block should read "scales as recommended that paper sizes be based on the

If a drawing has predominantly one scale, the "A" series and these sizes are specified in AS 1100

main scale should be shown in the title block together Part 101.' This series is particularly suitable forwith the notation "or as shown" to indicate the use reduction onto 35 mm microfilm because the ratio

of other scales elsewhere on the drawing of 1:V2.is constant for the sides of the paper (Fig.Sometimes it is necessary to use different scales 1.3(a)) and this ratio is also used for the microfilm

on the one view, for example on a structural steel frame

truss where the cross-sections of mef'!1bers are Paper sizes are based on the AD size, which hasdrawn to a larger scale than the overall dimensions an area of 1 square metre This allows paper weights

of the truss Such variations are indicated on the to be expressed in grams per square metre

is illustrated in Figure 1.3(a) and (b), where the

Member cross-sections 1:10 size sheet can be divided up evenly into the variousTruss dimensions 1:100 other sizes simply by halving the sheet on the long

If a particular scale requirement needs to be used s~de in ~ach case T,his is shown in F!gure 1.3(c) The

on a drawing it may be shown by one of the following dimensions of metric sheets from size AD to A4 ~re

1 a scale shown on the drawing, for example: appropriate border widths for each sheet size

Non-preferred sheet series

The "8" series of sheet sizes provides for a range

of sheets designated by 81,82,83,84, etc., whichare intermediate between the A sizes Therelationship of the 8 and A sizes is shown in Figure1.3(b); 8 sizes are in broken outline

Thicknesses for the various types of line are divided The standard widths of rollsare-860 rnm and-61iTmm.into specific groups according to the size of drawing Drawing sheets· can be cut off the roll to suitsheet being used Figure 1.2 shows the metric sheet individual drawings

size, the line type and thickness applicable in each

case

Table 1.3 Details of grid references

Size of drawing

number of vertical zones designated (1, 2, etc.) 16 12 8 6 4

number of horizontal zones designated (A, 8, etc.) 12 8 6 4 4

8

Fig 1.7 Use of projection and dimensioning lines

Dimensioning

Dimension and projection lines Angular dimensions

These lines are thin, light, continuous type B lines Angular dimensions should be stated in degrees, indrawn outside the outline wherever possible degrees and minutes, or in degrees, minutes and

Projection lines are used as follows: seconds, for example 36.50,36030',36029 '30" A

1 to project from one view to another in order zero should be used to indicate an angle less than

2 to allow dimensions to be inserted-projection

lines indicate the extremities of a dimension

Dimension lines are necessary to indicate the Methods of dlmenslonmg

Figure 1.7 shows the use of projection and common use:

dimension lines with appropriate measurements 1 unidirectional, where the dimensions are

Figure 1.8 illustrates correct and incorrect that is horizontal

methods of employing centre lines and projection 2 aligned, where the dimensions are drawnlines for dimensioning purposes parallel to the related dimension line and are

readable from the bottom or right-hand side of

Linear dimensions Dimensions and notes indicated by leaders shouldThese should preferably be expressed in millimetres use the unidirectional method The two methods are

It is not necessary to write the symbol "mm" after illustrated in Figure 1.9

every figure A general note such as "all dimensions

are in millimetres" in the title block is sufficient

12

Fig 1.10 Use of staggered dimensions

Staggered dimensions

Where a number of parallel dimensions are close

together they should be staggered to ensure clear

reading, as shown in Figure 1.10

Overall dimensions

When a length consists of a number of dimensions,

an overall dimension may be shown outside the

dimensions concerned (see Fig 1.11) The end

projection lines are extended to allow this When an

overall dimension is shown, however, one or more

of the dimensions which make up the overall length

is omitted This is done to allow for variations in sizes

which may occur during production The omitted

dimension is always a non-functional dimension, that

is, one which does not affect the function of the

product Functional dimensions are those which are

necessary for the operation of the product; these

dimensions are essential

Auxiliary dimensions

When all the dimensions which add up to give an

overall length are given, the overall dimension may

be added as an auxiliary dimension This is indicated

by enclosing the dimension in brackets

Auxiliary dimensions are never toleranced and are

in no way binding as far as machining operations are Dimensions not to scale

concerned Figure 1.12 illustrates the use of an When it is desirable to indicate that a dimension isauxiliary dimension, namely (100) not drawn to scale, the dimension is underlined with

If the overall length dimension is important, then a full, heavy, type A line, for example:

one of the intermediate dimensions is redundant, for

example the width of the narrow groove in the centre

This dimension may be inserted as an auxiliary

14

Fig 1.13 Diameters dimensioned on end view

Dimensions not complete

Where a dimension is defining a feature that cannot

be completely inserted on a drawing; for example,

for a large distance or diameter the free end is

terminated in a double arrowhead pointing in the

direction the dimension would take if it could be

Side view

This may be indicated, as shown in Figure 1.14(a),

by the use of the symbol cppreceding the dimension

or, as shown in Figure 1.14(b), by the use of leaderswhich are at right angles to the outline in conjunctionwith the symbol cp.

Fig 1.14 Diameters dimensioned on side view

Fig 1.15 Methods of dimensioning radii and small spaces

Figure 1.15 illustrates methods of dimensioning these These are dimensioned as shown in Figure 1.16 Notefeatures A radius is preceded by the letter R Leaders the distinction made between spherical diametersshould pass through or be in line with the centres and spherical radii

of arcs to which they refer

Squares Holes

The symbol 0 is used to indicate a square section, Holes either go right through a material or go to a

as shown in Figure 1.17 certain depth, and this must be specified as well as

the diameter If no indication is given, a hole is taken

as going right through Figure 1.18 illustratesmethods of dimensioning holes using both end andtop views

Flanges

Bolt holes on flanges may be positioned round thePCD (pitch-circle diameter) by either of the methodsshown in Figure 1.19

Countersinks Spotfaces

These may be dimensioned by one of the methods These may be dimensioned by one of the methods

Counterbores

These may be dimensioned by one of the methods

shown in Figure 1.21

Chamfers Keys-square and rectangular

These may be dimensioned by one of the methods Methodsof dimensioningkeywaysin shafts and hubs,shown in Figure 1.23 both parallel and tapered, are shown in Figure 1.24,

together with suitable proportions for drawingrectangular keys

Note: For design purposes, correct keyway portions should be obtained from as 4235

pro-Part 1 (1977)

Woodruff keys Tapers

Methods of dimensioning Woodruff keyways in shafts Tapers are dimensioned by one of the four methodsand hubs, both parallel and tapered, are shown in shown in Figure 1.26

Figure 1.25

Screw threads Threads on assembly and special threads

The methods shown in Figure 1.27 are recommended two threads in assembly Figure 1.28(b) shows thefor right-hand or left-hand representation of screw assembly of t,,:,omembers by a stud mounted in onethreads The diameter (¢DIA) of a thread is the of them Special threads are usually represented bynominal size of the thread, for example for a 10 mm a scrap sectional view illustrating the form of thethread (M1 0, see p 23), DIA = 10 mm thread, as shown in Figure 1.28(c)

Designation of threaded members Figure 1.29 are recommended Where there is noWhen full and runout threads have to be possibilityof misreading,the runoutthreads need notdistinguished, the methods of designation shown in be dimensioned.

Dimensioning full and runout threads in holes important to have fully formed threads for a certainFigure 1.30 shows various methods used to d~pth, and dimensioning must be provided to controldimension threaded holes The diameter of the thread this.

is always preceded by the capital letter M, which

indicates metric threads

The coarse thread series is designated simply by

the letter M followed by a numeral, for example M12 •

However, fine threads should show the pitch of the The ISO metnc thread

thread as well, for example M12 x 1.25 Figure 1.31 shows the profile of the ISO metric

If it is not important, the runout threads need not thread, together with proportions of the various

be dimensioned However, in blind holes it is often defined parts of the thread

Graphical comparison of metric thread series Sometimes the drill size has to be rounded off toISOmetric threads are of two kinds: coarse and fine the next largest stock drill size; this can be obtainedthread A graphical comparison of these two series from Table 1.5.

is shown in Figure 1.32 Column 4 of Table 1.4 gives tapping sizes for

coarse threads in mild steel only; these will give approximately 75 per cent of the full depth of thread.Tappmg ~Ize and clearance holes for In most general engineering applications this depthISO metnc threads of thread is sufficient and desirable for the followingTappingsizes and clearance holes for metric threads reasons:

are shown in Table 1.4 In this table column 1 1 Tapping 100 per cent depth of threadrepresents first and second choices of thread necessitates about three times more powerdiameters The sizes listed under second choice than tapping 75 per cent

should be used only when it is not possible to use 2 The possibility of tap breakage isgreater assizes in the first choice column the depth of thread increases

The pitches listed in column 2 are compared on 3 The 100 per cent thread has only 5 per centthe graph in Figure 1.32.Thesepitches,togetherwith more strength than the 75 per cent thread.the correspondingfirst and second choice diameters 4 The amount of metal removed from a 75 per

of column 1, are those combinations which have cent depth thread is only 56 per cent of thatbeen recommended by the ISO as a selected removed for 100 per cent

"coarse" and "fine" series for screws, bolts, nuts and There are cases when a full depth thread isother threaded fasteners commonly used in most necessary,for exampleon machinesand in situationsgeneral engineering applications Column 3 is the where movement in the mating threads is to be kepttapping size for the coarse and fine series These to a minimum

values represent approximately 100 per cent full Column 5 of Table 1.4 gives three classes ofdepth of thread, and can be calculated simply by the clearance holes recommended for the various sizes

tapping drill size = outside diameter - pitch

3.3 = 4 - 0.724

Table 1.5 Stock sizes of metric drills (mm)

A sectional view is one which represents that part at 45° to the horizontal, right or left If the shape of

the section would bring the sectioning lines parallel

of an object which remains after a portion has been to one or more of the sides, another angle may beremoved It is used to reveal interior detail Only solid

used (Fig 1.34)

material which has been cut is sectioned The main

types of sectional views used in mechanical drawing

are illustrated on pages 29-31 As far as possible the Adjacent parts

general sectioning symbol (cross-hatching) should be In section, adjacent parts should have their

A useful aid for drawing equally spaced sectioning more than two parts are adjacent, as in Figurelines is shown in Figure 1.33(b) 1.35(b), they may be distinguished by varying the

spacing or the angle of the hatching lines

Dimensions

Dimensions may be inserted in sectioned areas byinterrupting the sectioning lines, as shown in Figure1.35(c)

A specific section is identified by letters placednear the arrows, and reference to the sectional view

is made by the letters, separated by a hyphen, forexample section A-A Where only one cutting plane

is used on a drawing, the letters may be omitted.The chain line may be simplified by omitting thethin part of the line, if clarity is not affected.Arrowheads may also be omitted when indicatingsymmetrical sectional views or when the sectionalview is drawn in the correct projection indicated onthe drawing (see Fig 1.1)

The identification of a cutting plane may beomitted when it is obvious that the section can only

be taken through one location Figure 1.37 shows asectional view which is obviously taken on the centreline of the other view

Sectioning thin areas

Sometimes the section plane passed through verythin areas which cannot be sectioned by normal 450hatching, for example gaskets, plastic sheet, packing,

These can be shown sectioned by placing section should be filled in as shown in Figure 1.38(a).lines around the edges of the area only, as in Figure If two or more thin areas are adjacent, a small

Section cutting plane: Application

Section cutting planes are denoted by a chain line

(type H) drawn across the part as shown in the front

view of Figure 1.36 Arrowheads indicate the face

of the section and the direction of viewing

Removed sections

These are similar to revolved sections except thatFig 1.39Exceptions to the general rule of sectioning the cross-section is r~moved clear of the mai~ outline

for the sake of clanty The removed section may

be located adjacent to the main view (Fig 1.41) or

As a general rule all material cut by a sectioning it refers The outline of a removed section is a thickplane is cross-hatched in orthogonal views but there line (type A).

are exceptions When the sectioning plane passes

through the centre of webs, shafts, bolts, rivets, keys,

pins and similar parts, they are not shown sectioned Part or local sections

but in outside view, as in Figure 1.39 Part or local sections may be taken at suitable places

on a component to show hidden detail The boundary

of the sections is drawn freehand using a type Cline,

The shape of the cross-section of a bar, arm, spoke

or ri~ may be illustrated by a revolved or interposed Aligned sections

section

The interposed section has detail adjacent to it In order to include detail on a sectional view whichremoved, and is drawn using a thick line (type A). is not located along one plane, the section plane mayThe revolved section has the cross-sectional be bent to pass through such detail The sectionalshape revolved in position with adjacent detail drawn view then shows the detail along the line of the bentagainst the revolved view It is drawn using a thin cutting plane without ~n~ ind!c~tion that t~e ~Ianeline (type B). Figure 1.40 illustrates these two has been bent The pnnclple ISIllustrated In Figure

on the front view, heavy lines are used where theplane changes direction

Figure 1.43(b) illustrates another use of an alignedsection, where detail such as holes located on a pitchcircle are considered to be rotated into the cuttingplane and projected on to the sectional view at theiractual distance from the centre line

Fig 1.43 Aligned sections

Drawing sectional views The fuR sectional view

In most cases the normal outside views obtained Figure 1.44 shows an isometric view of a machinedfrom orthogonal projection are not sufficient to block which has been cut through the centre andcomplete the shape description of an engineering moved apart The shape and detail of thecomponent, both inside and out Hence other views counterbored holes are revealed along the face of

of a different type must be drawn in conjunction with, the cut This is the purpose of the sectional

view-or instead of, the nview-ormal outside views These special to reveal interior detail A normal view would be taken

views are called sectional views and the main types from position X

used in mechanical drawings are described in this Figure 1.45 shows the sectional view and a right

course of the sectioning plane is indicated by A-A

on the side view The direction of the arrows on thesection plane A-A indicates the direction from whichthe section is viewed

The offset sectional view

With a full sectional view, interior detail which liesalong one plane only is revealed Sometimes it isdesirable to show detail which lies along two or moreplanes, and this is done by means of the offsetsectional view

Figure 1.46 is an isometric view of a shaft bracketwhich has been cut by an offset sectioning plane toreveal the detail of the two bosses The offsetsectional view in this case is taken looking down onthe bottom piece as shown Figure 1.47 shows anormal front view and an offset sectional top view

of the bracket; the course of the sectional plane isshown by A-A

Note that there is no line shown on the sectionalview where the course of the sectioning planechanges direction

The half sectional view

This type of view is often used on objects which aresymmetrical about a centre line The cutting planeeffectively removes a quarter of the object as shown

in Figure 1.48 The resulting view provides two views

in one, as one half shows interior detail and the otherhalf shows external detail This is illustrated in Figure1.49

As with the offset sectional view, the divisionbetween the external half and the internal half of theview is not indicated by a full line, but by a centreline Hidden detail is omitted from the sectioned half

of the view, but may be shown on the external half

if by so doing the internal shape description is madeclearer This is the case in Figure 1.49, where thehidden detail completes the internal holes revealed

in the sectioned half

Rules to remember when sectioning

1 A sectional view shows the part of thecomponent in front of the sectioning planearrows In third-angle projection the sectionalview is placed on the side behind thesectioning viewing plane, while in first-angleprojection it is placed on the side in front ofthe sectional viewing plane

2 Material which has been cut by the sectioningplane is cross-hatched Standard exceptionsare given on page 28

3 A sectional view must not have any full linesdrawn over cross-hatched areas A full linerepresents a corner or edge which cannot exist

on a face which has been cut by a plane

4 As a general rule, dimensions are not inserted

in cross-hatched areas, but where it isunavoidable, it may be done as shown on page

27

When representing welds on drawings, refer to AS

1101 Part 3 or to the various constructional codeswhere welding is required to conform to these codes.The following information has been taken from theabove standard

Welding terminology

Figure 1.50 illustrates the standard terminology forvarious elements of fillet and butt welds

Basic symbols Standard welding symbol

Basic symbols which are used to denote the type of The standard welding symbol used to represent weldsweld for gas and are, and resistance welding are on drawings is shown in Figure 1.51 The symbol canillustrated in Tables 1.6 and 1.7 A number of be used in many ways, and some simple examplesinstructional symbols used to impose certain are shown in Table 1.10

requirements on the actual welding operation are

shown in Table 1.8