Architectural Ruler
• Is a specialized ruler. It is used in making or
measuring from reduced scale drawings, such as
blueprints and floor plans. It is marked with a
range of calibrated scales (ratios).
• Architect's scale rulers used in Britain and other
metric areas are marked with ratios without
reference to a base unit. Therefore a drawing will
indicate both its scale and the unit of
measurement being used.
The paired scales are
Architectural Scale
• In the United States, and prior to metrification in Britain, Canada and Australia, architect's
scales are/were marked as a ratio of x inches-to-the-foot (typically written as x"=1'-0"). For
example one inch measured from a drawing with a scale of "one-inch-to-the-foot" is
equivalent to one foot in the real world (a scale of 1:12) whereas one inch measured from a
drawing with a scale of "two-inches-to-the-foot" is equivalent to six inches in the real world
(a scale of 1:6). It is not to be confused with a true unit less ratio (inches to inches)-- a 1:50
architectural scale would be a 1:60 unit less scale.
• Typical scales used in the United States are:
• Full scale, with inches divided into sixteenths of an inch
• The following scales are generally grouped in pairs using the same dual-numbered index
• three-inches-to-the-foot (3"=1'-0") (ratio equivalent 1:4)/one-and-one-half-inch-to-thefoot (1-1/2"=1'-0") (1:8)
• one-inch-to-the-foot (1"=1'-0") (1:12)/one-half-inch-to-the-foot (1/2"=1'-0") (1:24)
• three-quarters-inch-to-the-foot (3/4"=1'-0") (1:16)/three-eighths-inch-to-the-foot
(3/8"=1'-0") (1:32)
• one-quarter-inch-to-the-foot (1/4"=1'-0") (1:48)/one-eighth-inch-to-the-foot (1/8"=1'-0")
• three-sixteenths-inch-to-the-foot (3/16"=1'-0") (1:64)/three-thirty-seconds-inch-to-thefoot (3/32"=1'0") (1:128)
Engineers Scale Ruler
• An engineer's scale is a tool for measuring
distances and transferring measurements at a fixed
ratio of length. It is commonly made of plastic and is
just over twelve inches (300 mm) long, so that the
measuring ticks at the edges do not become
unusable by wear. It is used in making engineering
drawings, commonly called blueprints, in scale. For
example, "one-tenth size" would appear on a
drawing to indicate a part larger than the paper
itself. It is not to be used to measure machined parts
to see if they meet specifications.
• The engineer's scale came into existence when
machining parts required a greater precision
than the usual, binary fractionalization of the
inch as in the architect's scale for houses and
furniture. They were used, for example, in laying
out printed circuit boards with the spacing of
leads from integrated circuit chips as one-tenth
of an inch. In the twenty-first century, those
which are commonly purchased in the US are
actually made in Germany.
• An engineer's scale, although identical at first
glance to the architect's scale, it has a different
set of measurements.
Typical engineering scales
1:01 FULL
1:02 6"=1'-0"
1:04 3"=1'-0"
1:16 3/4"=1'-0"
1:24 1/2"=1'-0"
1:32 3/8"=1'-0"
1:48 1/4"=1'-0"
0.08611111 3/16"=1'-0"
0.10833333 1/8"=1'-0"
0.13055556 3/32"=1'-0"
1:08 1-1/2"=1'-0"
How to Read a Scaled Ruler?
• Locate appropriate scale factor at end of scale ruler
• Place line or object to be measured at zero
• Read measurements from side of scale factor to end of line or object
▫ Scale factor on left = Read measurements from left to right
▫ Scale factor on right = Read measurements from right to left
• Be careful to read measurements from lowest to greatest (ascending) order
• Be careful not to read measurements from scale factor from other end of
scale ruler
• To measure foot increment, move scale ruler to lowest foot increment and
• To measure inch increment, measure line or object from left of zero (scale
factor on left) or right of zero (scale factor on right)
▫ Note: Measurements from zero to scale factor are 12 inches or 1 foot
▫ Determine measurements by determining 3”, 6” and 9” increments first
• Record measurement in foot and inches. Do not forget symbols for foot ( ‘ )
and inches ( “ )
• Read and Work on Scale Ruler Worksheets
▫ These are worth 35point total
• Day 2
▫ Quiz On Friday Over Material
Engineering Drawing
• An engineering drawing, a type of technical
drawing, is created within the technical drawing
discipline, and used to fully and clearly define
requirements for engineered items.
Types of Drafting
Engineering drawing
Cutaway drawings
Exploded view drawing
Patent drawing
Technical illustrations
Technical sketches
Working drawings
• Drafters prepare technical drawings and plans,
which are used to build everything from
manufactured products such as toys, toasters,
industrial machinery, and spacecraft to
structures such as houses, office buildings, and
oil and gas pipelines.
Drafting Specialties
Drafting work has many specialties:
Aeronautical drafters prepare engineering drawings detailing plans and
specifications used in the manufacture of aircraft, missiles, and related parts.
Architectural drafters draw architectural and structural features of buildings and
other structures. These workers may specialize in a type of structure, such as
residential or commercial, or in a kind of material used, such as reinforced
concrete, masonry, steel, or timber.
Civil drafters prepare drawings and topographical and relief maps used in major
construction or civil engineering projects, such as highways, bridges, pipelines,
flood control projects, and water and sewage systems.
Electrical drafters prepare wiring and layout diagrams used by workers who erect,
install, and repair electrical equipment and wiring in communication centers,
power plants, electrical distribution systems, and buildings.
Electronics drafters draw wiring diagrams, circuit board assembly diagrams,
schematics, and layout drawings used in the manufacture, installation, and repair
of electronic devices and components.
Mechanical drafters prepare drawings showing the detail and assembly of a wide
variety of machinery and mechanical devices, indicating dimensions, fastening
methods, and other requirements.
Process piping or pipeline drafters prepare drawings used in the layout,
construction, and operation of oil and gas fields, refineries, chemical plants, and
process piping systems.
Manual Drafting
• The basic drafting
procedure is to place a piece
of paper (or other material)
on a smooth surface with
right-angle corners and
straight sides—typically a
drafting table. A sliding
straightedge known as a Tsquare is then placed on
one of the sides, allowing it
to be slid across the side of
the table, and over the
surface of the paper.
Manual Drafting
• Parallel lines" can be drawn simply by moving the T-square
and running a pencil or technical pen along the T-square's
edge, but more typically the T-square is used as a tool to hold
other devices such as set squares or triangles. In this case the
drafter places one or more triangles of known angles on the
T-square—which is itself at right angles to the edge of the
table—and can then draw lines at any chosen angle to others
on the page. Modern drafting tables (which have by now
largely been replaced by CAD workstations) come equipped
with a parallel rule that is supported on both sides of the
table to slide over a large piece of paper. Because it is secured
on both sides, lines drawn along the edge are guaranteed to
be parallel.
• In addition, the drafter uses several tools to draw curves and
circles. Primary among these are the compasses, used for
drawing simple arcs and circles, and the: French curve,
typically a piece of plastic with complex curves on it. A spline
is a rubber coated articulated metal that can be manually
bent to most curves.
Line Conventions
Line Conventions
Lines of varying style and thickness are used in
specific ways to develop and communicate graphic
messages about an object’s geometry. The next few
slides show some basic line conventions and their
Line Conventions
Construction Line: Very
lightly drawn lines used
as guides to help draw
all other lines and
shapes properly.
Line Conventions
Object Lines: Lines are thick
and dark; used to define the
Object Line
Object Line
Line Conventions
Hidden Line: Lines used to show
interior detail that is not visible from the
outside of the part.
Hidden Line
Hidden Line
Line Conventions
Center Line: Lines
that define
the center of arcs,
circles, or
Symmetrical parts.
They are half as
thick as an object
Center Line
Center Line
Line Conventions
Section Lines: Lines are
used to define where there
is material after a part of
the object is cut away.
Section Line
Section Line
Line Conventions
Short-Break Line:
A freehand drawn
line that shows
where a part is
broken to reveal
detail behind the
part or to shorten
a long continuous
Line Conventions
• Dimension Lines: Lines
that are used to show
• Arrows are drawn on the
ends to show where the
dimension line starts and
• The actual distance is
usually located in the
middle of this line to let
you know the distance
being communicated.
Line Conventions
• Extension Lines: Lines
used to show where a
dimension starts and
stops on an object.
• Used with dimension
lines to properly
dimension an object.
• The line is 1/16” away
from the part as to not
get confused with the
object lines.
Line Conventions
• Long-Break Lines:
Used to shorten very
long objects that do
not change in detail.
• The line is usually
represented as a
jagged cut or break.
Line Conventions
• Leader Lines: Leader
lines are used to show
dimensions of arcs,
circles and to help
show detail.
Leader Line
Leader Line
Line Conventions
Though these standards relate to technical
drawing, which is far more precise than
freehand sketching, their conventions
should be used as a guide when sketching.
Precedence of Lines
When sketching complex objects,
different line types will often overlap
each other. Therefore, line
precedence must be exercised.
Precedence of Lines
The following are rules that govern line precedence
in sketches and technical drawings.
• Object lines take precedence over hidden and center
• Hidden lines take precedence over center lines.
• Cutting plane lines take precedence over all others.
Precedence of Lines
Object lines take precedence over
the hidden lines.
An object line here takes
precedence over the center line.
Precedence of Lines
• Object lines take
precedence over the
center lines you
would see from the
• Object lines take
precedence over the
hidden lines you
would see from the
slot cut out in top
An object line here takes
precedence over the hidden line.
An object line here takes
precedence over the center line.
Technical Sketch
Like an artist may use sketches to develop ideas for a painting or sculpture,
technical sketches are used during the development of ideas for initial or
preliminary plans. The ability to make quick and accurate sketches is a valuable
advantage that helps you convey design ideas to others. A sketch may be of an
object, an idea of something you are thinking about, or a combination of both.
Most of us think of a sketch as a freehand drawing, which is not always the case.
You may sketch on graph paper to take advantage of the lined squares, or you
may sketch on plain paper with or without the help of drawing instruments.
Technical sketches are drawn without mechanical aid, like a t-square, compass,
or straight edge, but, like other forms of architectural drafting, are drawn to scale
and contain a variety of line weights and line styles (Figure 1). The pencil or pen
is guided by the hand of the drafter alone and this is usually done on trace paper
over a 1/4" grid paper. The grid paper becomes the guide helping to keep lines
• Lettering is used on drawings to give dimensions
and other pertinent information needed to fully
describe the item.
• The lettering must be neat and legible if it is to
be easily read and understood.
• A drawing will be improved by good lettering.
• However, a good drawing will look sloppy and
unprofessional if the lettering is poorly done.
Lettering, Continued…
• The American National Standards Institute
(ANSI) recommends that the Single-Stroke
Gothic Alphabet be the accepted lettering
Lettering, Continued…
• It can be drawn rapidly and is highly legible
because each part of every letter is made by a
single stroke.
Lettering, Continued…
• This is because there are no serifs on the letters
of this alphabet.
▫ A serif is like a tiny foot on a letter; alphabets that
have serifs are more difficult to letter by hand. An
alphabet without serifs is always called a san serif
Lettering, Continued…
• Today, because of
computers, there are many
different alphabet styles
(also called fonts).
▫ When lettering a drawing, if
the single stroke Gothic
alphabet is not available,
choose a san serif font and use
only upper case letters.
Good Lettering, Continued…
• Use guide lines
▫ Guide lines should be drawn so lightly they will
not show up on a print made from the drawing
▫ Vertical guide lines may be used to assure that the
letters will be vertical
▫ Inclined guide lines are drawn at 67 1/20 to the
horizontal line when inclined lettering is to be
Good Lettering, Continued…
• Only one form of lettering should appear on a
Lettering, Continued…
• Spacing:
▫ Proper spacing of the letters is important.
▫ The letters should be placed so spaces between the
letters appear to be about the same.