Engineering Drawing Project
Engineering Drawing (FCE – 142)

Group Members

Standard Engineering Lettering
and Lines

Elements of Engineering Drawing
Engineering drawing are made up of graphics
language and word language.
Graphics language
Describe a shape (mainly).
Word language
Describe an exact size,
location and specification
of the object.

Elements of Engineering Drawing
Graphics
language
Word
language
Lettering
Line Types
Geometric
construction
Projection
method
Engineering Drawing

Introduction to Types of Lines
• Each line has a definite form and line weight.
• The standard thick line weight is 0.6mm HB Lead.
• The standard thin line weight is 0.3mm HB Lead.
• The standard construction line weight is 0.5mm 2H
Lead.

Basic Line Types &
Name according to application
Continuous
Dash
Chain
Style
Thickness Thick Thin 1. Dimension line
2. Extension line
3. Leader line
Center line
Hidden line
Visible line
represent features that can be seen in the current view.
represent features that cannot be seen in the current view.
represents symmetry, path of motion, centers of circles,
axis of axisymmetrical parts.
indicate the sizes and location of features.
1. Visible line
3. Hidden line
4. Center line
2. Dimension line
Extension line
Leader line

Main Line Types
Lines
Hidden Lines
Center Lines
Dimension Lines
Extension Lines
Leader LinesCutting Planes
Section Lines
Phantom Lines
Viewing Planes
Break Lines
Visible Lines

Visible/Object Lines
• Dark, heavy lines.
• Used to represent the outline or contour of the object
being drawn.
• Define features you can see in a particular view.

Hidden Lines
• Light, narrow, short, dashed lines.
• Shows the outline of a feature that can not be seen in
a particular view.
• Used to help clarify a feature, but can be omitted if
they clutter a drawing.

Hidden Lines (Technique)

Section Lines
• Thin line usually drawn at a 45 degree angle.
• Indicates the material that has been cut through in a
sectional view.
Section
Line

Center Lines
• Thin line consisting of alternating long and short
dashes.
• Used to represent the center of round or cylindrical
features, or the symmetry of a feature.

Dimension Lines
• Thin lines capped on the ends with arrowheads and
broken along their length to provide a space for the
dimension numeral.
• They indicate length.

Extension Lines
• Thin lines used to establish the extent of a dimension.
• Can also be used to show extension of a surface to a
theoretical intersection as shown in (b).
• Begin 1.5mm from the object and extend to 3mm
beyond the last dimension.
• They should not cross dimension lines.

Leader Lines
• Thin lines used to connect a specific note to a feature.
• Also used to direct dimensions, symbols, item number and
part numbers on a drawing.
• Commonly drawn at 45, 30 and 60 degrees.
• Has a short shoulder (3-6mm) at one end beginning at the
center of the vertical height of text, and a standard
dimension arrowhead at the other end touching the feature.
• Leader lines should not cross
each other.
• Leader lines should not be
excessively long.
• Leader lines should not be
vertical or horizontal.
• Leader lines should not be
parallel to dimension lines,
extension lines or section lines.

Arrowheads
• Used to terminate dimension lines and leader lines and on
cutting-plane lines and viewing plane lines.
• They should be three times as long as they are wide.
• They should be the same size throughout the drawing.
• The filled arrowhead is generally preferred because of its
clarity.

Cutting Plane Lines
• Thick broken line that is terminated with short 90
degree arrowheads.
• Shows where a part is mentally cut in half to better
see the interior detail.

Cutting Plane Lines (Example)

Break Lines
• Used to break out sections for clarity or for shortening
a part.
• Three types of break lines with different line weights:
a) Short Breaks.
b) Long Breaks.
c) Cylindrical Breaks.

a) Short Break Lines
• Thick wavy line.
• Used to break the edge or surface of a part for clarity
of a hidden surface.
(a) Short break line on metal shape;
(b) Short Break Line on wood shape.

b) Long Break Lines
• Long, thin lines.
• Used to show that the middle section of an object has
been removed so it can be drawn on a smaller piece
of paper.

c) Cylindrical Break Lines
• Thin lines.
• Used to show round parts that are broken in half to
better clarify the print or to reduce the length of the
object.
Cylindrical conventional breaks for a solid and tube;
where R = Radius

Phantom Lines
• Thin lines made up of long dashes alternating with
pairs of short dashes.
• Three purposes in drawings
a) To show the alternate position of moving parts.
b) To show the relationship of parts that fit together.
c) To show repeated detail.

Phantom Lines (Examples)

Grades of Pencils used in Lines

Example 1

Example 2

Lettering in Engineering Drawing
Lettering is used to provide easy to read and understand
information to supplement a drawing in the form of notes
and annotations.
Thus, it must be written with:
Legibility – shape & space between letters and words.
Uniformity – size & line thickness.
Lettering is an essential element in both traditional drawing
and Computer Aided Design (CAD) drawing

Types of Lettering
The two types of lettering are:
1.Double Stroke Lettering.
2.Single Stroke Lettering.

1. Double Stroke Lettering
In Double Stroke Lettering the line width is greater than that of
Single Stroke Lettering.
Double Stroke Lettering is further divided into:
a)Double Stroke Vertical Gothic Lettering.
b)Double Stroke Inclined Gothic Lettering.
A stencil is mostly used when hand drawing double stroked letters.

2. Single Stroke Lettering
Thickness in single stroke lettering is obtained by a single stroke of
pencil or ink pen.
It is further divided into:
(a) Single Stroke Vertical Gothic Lettering.
(b) Single Stroke Inclined Gothic Lettering.
Single stroke vertical letters Single stroke inclined letters

Conventions for Lettering
• Use all CAPITAL LETTERS.
• Use even pressure to draw precise, clean lines.
• Use one stroke per line.
• Horizontal Stroke are drawn left to right.
• Vertical Strokes are drawn downward.
• Curved strokes are drawn top to bottom in one continuous stroke on
each side.
• Use kerning to eliminate excessive space between letters. –
[kerning refers to adjusting the space between characters, especially by
placing two characters closer together than normal. Kerning makes certain
combinations of letters, such as WA, MW, TA, and VA, look better.]

Conventions for Lettering (cont.)
• Use The Single-stroke, Gothic Style of Lettering.
• Always Skip A Space Between Rows Of Letters.
• Always Use Very Light Guide Lines.
• Fractions Are Lettered Twice The Height Of Normal Letters.
• Fraction Bars Are Always Drawn Horizontal.
• Use a Medium (B, HB, F or H) Lead For Normal Lettering.
• Use a Hard (2H To 4H) Lead For Drawing Guide Lines.
• Notes should be double spaced.

Application of Lettering
Lettering in Engineering Drawings is used in writing
Title Blocks which play a crucial role in drawings, they
are used to record all of the important information
necessary for the working drawings. A HB Pencil is used.
What does the Title Block contain?
Other uses of lettering include Dimensions and Notes
on the engineering drawing.

Placement of text on Engineering Drawings
Try and locate the text on the drawings going around.

Guidelines
Extremely light horizontal lines that are necessary to regulate
the height of letters.
In addition, light vertical or inclined guidelines are needed to
keep the letters uniformly vertical or inclined.
Guidelines are absolutely essential for good lettering.
Guidelines are drawn using Hard (2H to 4H) Lead Pencils with
light pressure. HB grade conical end pencils are used for
lettering.
Procedure for Lettering
• Thin horizontal guide lines are drawn first at a distance ‘h’ apart.
• Lettering Technique: Horizontal lines of the letters are drawn from
left to right. Vertical, inclined and curved lines are drawn from top to
bottom.
• After lettering has been completed, the guidelines are not erased.

Guidelines in Lettering (including Height)
h
c1
c2
c3
b1
b2
-(height of capital letters)
-(height of lower-case letters)
-(tail of lower-case letters)
-(stem of lower-case letters)
-(spacing between baselines)
-(spacing between baselines)
Recommended Size (height, h) of
Letters/Numerals
Main Title 5mm, 7mm, 10mm
Sub-Title 3.5mm, 5mm
Dimensions, Notes
etc.
2.5mm, 3.5mm, 5mm
h
c2
c2

Guidelines for Lettering
• Drawing numbers, title blocks and letters denoting cutting planes,
sections are written in 10mm size.
• Drawing title is written in 7mm size.
• Hatching, subtitles, materials, dimensions, notes etc. are written in 3.5
mm size.
• Space between lines is 3/10 h (height of capital letters)
• Space between words may be equal to the width of the alphabet M or
3/5 h (height of capital letters).
Standard height for CAPITAL Letters and Numerals according to the Bureau of
Indian Standards (BIS) is:
1.8, 2.5, 3.5, 5, 6, 10, 14, 20 mm. (Sizes selected based upon size of drawing)

Guidelines for Lettering

Basics of Single Stroking
Straight Slanted CurvedHorizontal
1 1 2
3
“I” letter “A” letter
1
2
3
4 5
6
“B” letter
Examples

Order of Strokes
Stroking is done based on the slope of each letter and
the strokes vary with order and direction.

Various Single Stroking
Groups

Stroking for Upper Case Letters & Numerals
Straight line
letters
Curved line
letters
&
Numerals

Stroking for Lower Case Letters

Stroking Groups
The I-H-T Group
•The letter I is The Foundation Stroke.
•The top of T is drawn first to the full width of the square and
the stem is started accurately at its mid point.
I H T

Stroking Groups
The L-E-F Group
•The L is made in two strokes.
•The first two strokes of the E are the same for the L, the
third or the upper stoke is lightly shorter than the lower and
the last stroke is the third as long as the lower.
•F has the same proportion as E.
L E F

Stroking Groups
The V-A-K Group
•V is the same width as A, the A bridge is one third up from
the bottom.
•The second stroke of K strikes stem one third up from the
bottom and the third stroke branches from it.
V A K

Stroking Groups
The M-W Group
•Are the widest letters.
•M may be made in consecutive strokes of the two verticals
as of N.
•W is made with two V’s.
M W

Stroking Groups
The O-Q-C-G Group
•The O families are made as full circles and made in two
strokes with the left side a longer arc than the right.
•A large size C and G can be made more accurately with an
extra stroke at the top.
O Q C G
The O-Q-C-G Group stroking will be demonstrated on the
whiteboard

Stroking Groups
The O-Q-C-G Group (cont.)

Stroking Groups
The D-U-J Group
•The top and bottom stokes of D must be horizontal, fail line
to observe this is a common fault with beginners
•U is formed by two parallel strokes to which the bottom
stroke be added.
•J has the same construction as U, with the first stroke
omitted.
D U J
Note:- The
bottom stroke
in J is drawn
once, and not
twice as
shown in the
animation.

Stroking Groups
The P-R-B Group
•The number of stokes depends up on the size of the letter.
•The middle line of P and R are on centerline of the vertical
line.
P R B

Stroking Groups
The N-Z-X-Y Group
•The parallel sides of N are generally drawn first.
•Z is drawn without lifting the pen. Z and X are both
started inside the width of the square on top and run to
full width on the bottom.
N Z X Y

Other Stroking Groups
The S-8-3 Group
The 0-6-9 Group
A perfect 3 should be
able to be completed
into an 8; An 8 can be
made from an S
construction. The S is
made up of three
strokes.
The cipher (zero) is
narrower than the
letter O and made of
two strokes. The 6
and 9 have the cipher
as their backbone.
With their lobes 2/3
the figure’s height.

Other Stroking Groups
The 2-5-7-& Group
The Fraction Group
• Always made with a horizontal vinculum (a horizontal line used in
mathematical notation).
• The figures are two-thirds the height of the whole numbers, with a clear
space above and below the line, making the total height of the fraction nearly
twice the cap height (h).
The bottom of 2 and top of 5 and 7 should be straight lines. For 2 the reverse curve should cross
the center of the space. The ampersand (&) is made of three strokes.

The Fraction Group (Example)

Sample Video
(showing single stoking in lettering)

Spacing
Uniformity in spacing of letters is a matter of equalizing
spaces by eye.
•The background area between letters, not the distance between them,
should be approximately equal.
•Words are spaced well apart, but letters within words should be spaced
closely.
•For either upper case or lower-case lettering, make the spaces between
words approximately equal to a capital O.
•Avoid spacing letters too far apart and words too close together.
LINES AND LETTERINGS
L IN E S
T T E RSEL

Types of Spacing

Space between letters
Contour
DRAWING
Contour can be denoted as straight, slant and curve.
Adjacent contour can be
1. straight-straight : II, IN, IM, IP etc.
2. straight-curve (or curve-straight) : IO, QR etc.
3. straight-slant (or slant-straight) : IV, IW etc.
4. curve-curve : OO, OG etc.
5. slant-curve (or curve-slant) : VO, WG, VC etc.
6. slant-slant : VW, VX etc.
7. The ‘L’ and ‘T’ : LT

Space between letters

Space between letters

Lettering Uniformity
• Important to produce good drawings.
• Uniform in style, size, inclination, weight and space.
• Carelessness might result in mistakes.
ENGINEERING DRAWINGS
Space between letters
• Spacing between characters, is normally (2/10)h.
• Spacing between words, is normally (6/10)h.
where h is the cap height.

Examples of Common Mistakes
in Lettering
L E t T E r I N G
L E T T E R I N G
L E T T E R I N G
LET T E R ING
L E T T E R I N G
Lettering style not uniform
Lettering height not uniform
Lettering inclination not uniform
Lettering thickness not uniform
Lettering space not uniform

References
French, T. E., (1918). A MANUAL OF ENGINEERING
DRAWING FOR STUDENTS AND DRAFTSMEN. London: Hill
Publishing Co., Ltd.
Engineering Drawing Fundamentals: Introduction to
Engineering Drawing. Retrieved from
http://pioneer.netserv.chula.ac.th/~kjirapon/lecture-
note.html.
Madsen D. A., Madsen D. P., (2011). ENGINEERING
DRAWING & DESIGN, Fifth Edition. New York: Cengage
Learning.
Reddy K. V., (2008). TEXTBOOK OF ENGINEERING
DRAWING. Hyderabad: BS Publications.

THE END