1. Introduction to Drafting and Design
Scales
Today’s presentation is going to be about the different types of scales and how we measure drawings using each of these scales.
Introduction to Drafting and Design

2. What is a scale?
So what exactly is a Scale?

3. Scale There are two different meanings for the word scale
The size to which an object is drawn
An instrument with a system of ordered marks at fixed intervals used as reference standards in measurements.
A scale establishes a proportion used in determining the dimensional relationship of an actual object to the representation of the same object on a drawing.
There are actually two different meaning for the word “scale”
The first meaning is the size to which an object is draw. Objects can be drawn larger to scale or smaller to scale depending on the type of object.
The second meaning is an instrument with a system of ordered marks at fixed intervals used as reference standards in measurement. These are the instruments that some people get confused with rulers. The scale may look to the untrained eye like a six-sided ruler. But these are not rulers, they are scales!
A scale establishes a proportion used in determining the dimensional relationship of an actual object to the representation of the same object on a drawing. If you have a small item such as a dime but you wanted to draw it to fit on an entire sheet of paper, you would be increasing the scale of the dime.

4. What are the different types of scales?
Drafters use the word scale to name the instrument, but there are several different types and styles of scales used in architectural, engineering, and mechanical drawings.

5. Types of Scales There are four different shapes of scales:
Two Bevel
Four Bevel
Opposite Bevel
Triangular
Triangular shaped scales are the most common scale used.
Below are the types of scales used by drafters.
There are four different shapes of scales
Two bevel, four bevel, opposite bevel and triangular bevel.
You can see a cross-hatch picture of each shape to the right of the screen.
Triangular shaped scales are the most common scale used. This is because a triangular scale can hold up to 12 different scales and it eliminates the need to have multiple scales cluttering your work station.

6. Types of Scales
There are three major scales are used in today’s industries
Architect Scale
Engineer Scale
Metric Scale
In addition to the different shapes of scales, there are also different types of scales that serve different purposes.
The three different scales that we will be discussing are architect scale, engineer scale, and the metric scale.

7. Architect Scale
Used to make drawings of buildings and building detail
Six sided with 11 different scales
Common scales on an architect scale other than the “full” scale of 16
The 16 or full scale is a standard ruler with each mark representing 1/16” of an inch
The scales are usually grouped together when one factor is twice the other
When scales are grouped together, one of the scales is read from one end of the instrument and the other scale is read from the opposite end.
1/8” = 1’-0”
1/4” = 1’-0”
1/2”= 1’-0”
1” = 1’-0”
1 1/2” = 1’-0”
3” = 1’-0”
An architecture scale is used by architects to create drawings of buildings and building details.
Most architect scales are triangular so therefore they have six sides with eleven different scales. Though the scale could hold 12 total, on one side, you will find the standard 16 scale and only reads in one direction. The other 5 sides feature two scales that can be read from left to right and from right to left. Together on this six sided scale, drafters are able to use 11 scales when needed.
The most common scales on an architect’s scale are in the following table.
The 16 or full scale is the standard ruler with each mark representing 1/16th of an inch
The other ten scales are grouped together when one scale is twice the size of another one

8. Civil Engineer’s Scale
Engineer Scale
Also known as a civil scale
Is used for measuring length and transferring length of larger scale plans such as site plans
An Engineer Scale is divided into 6 scales
Civil Engineer’s Scale
Divisions
Ratio
Scales Used with this Division 10
1:1
1” = 1”
1” = 1’
1” = 10’
1” = 100’ 20
1:2
1” = 2”
1” = 2’
1” = 20’
1” = 200’ 30
1:3
1” = 3”
1” = 3’
1” = 30’
1” = 300’ 40
1:4
1” = 4”
1” = 4’
1” = 40’
1” = 400’ 50
1:5
1” = 5”
1” = 5’
1” = 50’
1” = 500’ 60
1:6
1” = 6”
1” = 6’
1” = 60
1” = 600’
An Engineer scale is also known as a civil scale because it is mostly used by civil engineers.
It is primarily used for measuring length and transferring length of larger scale plans such as site plans for architectural structures.
Engineer scales are triangular and contain six scales.
The scales are listed in the table below.
For example, if you have the ratio of 1:2, you can have that ratio stand for inches, feet, tens of feet or hundreds of feet. Lets say we have a line that is 5 inches long and you have a ratio of 1 inch equals 4 inches, then the secondary line is 5 inches times 4 inches which equals a line of 20 inches

9. Engineer Scale
The engineer scale and the architect scale are similar in appearance
The engineer scale is designed to be more precise by using a decimal scaling scheme
Whereas an architect’s scale uses fractional scaling.
Engineer scales are only read from left to right where architect scales can be read from left to right and right to left.
Although the engineer scale and the architect scale are similar in appearance, the engineer scale is designed to be more precise by using a decimal scaling system whereas an architect’s scale uses fractional scaling.
Engineer scales are only read from left to right where as architect scales can be read from left to right and right to left.

10. Metric Scale Used for drawings made in metric units or meters
The metric scale uses ratios
Metric Scales
Full Scale
1:1
Half Scale
1:2
One fifth Scale
1:5
One twenty-fifth Scale
1:25
One thirty-three and one-third Scale
1:33 1/3
One seventy-fifth Scale
1:75
The final scale that we are going to be talking about is the metric scale.
The metric scale is used on drawings that use the metric system in their dimensioning.
The metric system is when measurements are in centimeter, millimeter, etc.
The metric scale uses ratios such as the following.

11. How do we use each scale?
Now that we know the different types of scale, how do we use each the scales properly?

12. How do we use all of the scales?
To make a measurement, observe the scale from directly above.
Mark the desired measurement on the paper by using a light perpendicular line made with a sharp pencil
Keep you scale clean
DO NOT mark on the scale itself
DO NOT use the scale to draw straight lines
Here are a few tips to follow no matter what scale you are using.
To make a measurement, observe the scale from directly above. This allows for you to get a good angle of view and get an accurate reading.
Mark the desired measurement on the paper by using a light perpendicular line made with a sharp pencil.
Keep you scale clean at all times. This ensures that your measurement is accurate.
DO NOT mark on the scale itself
DO NOT use the scale to draw straight lines, that is what the T-square is used for.

13. Architect Scale
To take a measurement with an architect’s scale follow these steps:
Find the scale that matches the scale of the drawing
Align the zero mark of the scale with one side of the object
Read the foot measurement by finding the closest tick mark on the scale that is to the end of the object without going past the end of the object.
Then read the inch measurement by counting the number of small tick marks that are located past the large tick mark.
To make a measurement with an architect’s scale, follow these steps:
Find the scale that matches the scale of the drawing. The scale should be located within the legend or the title block of the drawing.
Align the zero tick mark up with the end of the object that you are wanting to measure or draw.
Read the foot measurement by finding the closet large tick mark on the scale that is to the end of the object without going past the end of the object.
Then read the inch measurement by counting the number of small tick marks that are located past the largest tick mark. The small tick marks are recorded as a fraction.
In this picture we can see several measurements that were taken. Notice the first number on the measurement corresponds with the last largest tick mark that the line passed. Use these notes as a reference in answering three different measurements on the next slide.

14. Examples Answer: 1 - 5/16 Answer: 2 – 1/16 Answer: 2 – 3/4
Now that you know how to use an architect’s scale, lets practice.
How long is this first line? If you said that the line is 1 and 5/16ths long, then you are correct.
How about the second line? The second line is 2 and 1/16th long.
Finally, lets do this third line. If you said that the line is 2 and 3/4ths inches long then you are right.
Answer: 2 – 3/4

15. Engineer Scale
To take a measurement with an engineer’s scale, first obtain the scale on the drawing.
The scale will either be in an inch to feet equality (1” = 20’) or a ratio (1:20)
Locate the matching scale on the engineer’s scale and line up the zero on the left side with the object being measured.
Find the tick mark that lines up with the other end.
Read the major marks and add the minor marks as the tenths and hundredths.
To use an engineering scale is not much different from an architect scale.
To make a measurement, you first find the scale located in the title block. With an engineer scale, the scale can either be written as an equality such as 1” = 20’ or as a ratio like 1:20
Once you have obtained the scale, located the corresponding scale on the instrument itself.
Find the tick mark that lines up with the other end of the object.
Be sure to read the major and as well as the minor marks
The minor marks should be read as decimals instead of fractions.

16. Examples Use the ratio 1” = 10’ Answer: 15.5’ Use the ratio 1” = 30’
Let’s try:
Determine the length of the lines by using the ratios given.
What did you answer for the first line, if you said 15.5 feet then you are correct.
Did you say 56 feet for the second line?
And for the final line did you get a length of 1150 feet.
If you got all of those correct then you can successfully read an engineering scale.
Use the ratio 1” = 600’
Answer: 1150’

17. Metric Scale Metric scales can be used to reduce or enlarge a drawing
Most metric drawings are drawn with a 1:1 metric scale.
To use a metric scale, find the correct ratio that matches the drawing ratio
Place the end of the object on the zero line
Find the large tick mark to indicate the tens, then use the little tick marks to find the ones and decimal numbers.
The final scale that we need to learn how to use is the metric scale.
Metric scales can be used to reduce or enlarge a drawing.
Most metric drawings are drawn with a 1:1 metric scale.
To use a metric scale, find the correct ratio that matches the desired drawing ratio.
Place the end of the object on the zero line.
Find the large tick mark to indicate the tens, the use the little tick marks to find the ones and decimal numbers.

18. Examples Answer: 75’ Answer: 92’ Answer: 460’
Let’s try these three examples out.
Notice the ratios increase but the lines decrease…what do we think this will do to the actual length of the objects?
Well the length of the lines are 75 feet, 92 feet and 460 feet, therefore the actual length increase.
Answer: 460’

19. How do you determine the scale of a drawing?
So how do you determine the scale of a drawing…

20. Scale of a Drawing
Scales are in constant use on the drawing board because accurate drawings are a must
To select a scale for a drawing you must consider the following about the drawing:
The actual size of the objects drawn
The amount of detail to show
The media size (size of paper used for drawing)
The amount of dimension and notes required
The scale of a drawing is listed in the title block of the drawing
Scales are in constant use on the drawing board because accurate drawings are a must in this industry. If you don’t have accurate drawings then the actual objects will not be accurate.
To select a scale for a drawing you must consider the following items about the drawing itself.
The actual size of the objects drawn
If the actual object is small then you will have a larger scale, but if you are dealing with a large item then you will have to scale it down.
The amount of detail to show
If you have an object that has a lot of detail, then you would need to scale the object in so that you are able to see all of the details.
The media size
If you have a small piece of paper, then you can’t scale some objects to their needed size, but if you are working with larger paper, then you can make a drawing bigger and more detailed.
The amount of dimensions and notes required
If a drawing requires a lot of dimensions then you will need to scale the drawing bigger so that the dimensions won’t be crowded and hard to read.
If you already have a drawing of your object, then the scale will be located within the title block of the drawing.

21. In summary …
There are three scales that we can use: architecture, engineering and metric scales
These scales can be either two bevel, four bevel, opposite bevel and triangular shaped
The triangular shape is the one that is used the most
Make sure to view the scale from above when making measurements and place the end of the line on the zero marker
Now take what you have learned in this presentation and complete Activity 8.1 – What’s the Scale?