1. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Dimensions
There are dozens of rules, dos and don’ts, and guidelines associated with dimensioning. The purpose of this presentation is to introduce those guidelines that are most critical. These 8 rules have been taken from the IED curriculum as the guidelines that we most want middle school students to recognize. You may use the IED presentation on Dimension Guidelines if you want to include the 16 guidelines that they discuss.

2. What are Dimensions?
Measurements that show size and location of features on an object!
Engineers need all these measure to manufacture parts—these drawings and dimensions are like BLUEPRINTS

3. Dimension Completely
Width
Height
Depth

4. Dimension Line Types
Dimension Line
Extension Line
Leader Line

5. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
1. Dimensions should NOT be duplicated, nor should the same information be given in two different ways.
Incorrect

6. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
1. Dimensions should NOT be duplicated, nor should the same information be given in two different ways.
References:
Pg 337 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 109 Fundamentals of Modern Drafting by Paul Wallach
Pg 425 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg 701 Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe
Correct

7. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
2. Dimensions should be attached to the view that best shows the contour of the feature to be dimensioned.
References:
Pg 342 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 405 & 425 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg 698, 700, Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe
It should be noted that the 2.00 inch dimension would be appropriately located if placed on the top view, but the front view is preferred because it is supposed to provide the most information about an object’s geometry.
Incorrect

8. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
2. Dimensions should be attached to the view that best shows the contour of the feature to be dimensioned.
References:
Pg 342 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 405 & 425 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg 698, 700, Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe
It should be noted that the 2.00 inch dimension would be appropriately located if placed on the top view, but the front view is preferred because it is supposed to provide the most information about an object’s geometry.
Correct

9. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
3. Whenever possible, avoid dimensioning to hidden lines.
References:
Pg 342 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 134 Fundamentals of Modern Drafting by Paul Wallach
Pg 426 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg 703 Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe
Incorrect

10. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
3. Whenever possible, avoid dimensioning to hidden lines.
References:
Pg 342 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 134 Fundamentals of Modern Drafting by Paul Wallach
Pg 426 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg 703 Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe

11. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
4. Avoid dimensioning over or through the object.
Incorrect
References:
Pg 342 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 394, 404, 426 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg 692 Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe

12. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
4. Avoid dimensioning over or through the object.
References:
Pg 342 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 394, 404, 426 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg 692 Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe

13. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
5. Whenever possible, locate dimensions between adjacent views.
Incorrect
References:
Pg 342 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 108 Fundamentals of Modern Drafting by Paul Wallach
Pg 426 Technical Drawing 9th Edition by Frederick Giesecke, et. al.

14. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
5. Whenever possible, locate dimensions between adjacent views.
References:
Pg 342 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 108 Fundamentals of Modern Drafting by Paul Wallach
Pg 426 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Notice this dimension is not between the views, but this is a better placement
than dimensioning to the hidden line in the right side view.

15. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
6. In general, a circle is dimensioned by its diameter and an arc by its radius.
References:
Pg , Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 131, Fundamentals of Modern Drafting by Paul Wallach
Pg , , 427 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg , Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe

16. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
7. Holes are located by their centerlines, which may be extended and used as extension lines.
References:
Pg 44, 340 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg , 426 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe

17. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
8. Holes should be located and sized in the view that shows the feature as a circle.
Incorrect
References:
Pg 351 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 109 Fundamentals of Modern Drafting by Paul Wallach
Pg 411, 427 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg 693 Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe

18. Dimensioning Guidelines
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
8. Holes should be located and sized in the view that shows the feature as a circle.
Correct
References:
Pg 351 Engineering Drawing and Design 3rd Edition by David Madsen, et. al.
Pg 109 Fundamentals of Modern Drafting by Paul Wallach
Pg 411, 427 Technical Drawing 9th Edition by Frederick Giesecke, et. al.
Pg 693 Technical Graphics Communication 3rd Edition by Gary Bertoline & Eric Wiebe
Note: The top view was removed because it is not needed to completely communicate the object’s geometry.

19. ¼ in. scale or 4 squares = 1 in.
Dimensioning
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Your Turn to Practice
¼ in. scale or 4 squares = 1 in.
Give students time to complete this in Activity Dimensioning before going on to the next slide.
Tell students that it is not good dimensioning practice to dimension to a hidden line.
A future presentation will describe the guidelines associated with dimensioning.

20. Check Your Answers Dimensioning Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Check Your Answers
Orthographic graph paper is removed to better show dimensions.

21. Where are the Missing Dimensions?
Dimensioning
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Where are the Missing Dimensions?
¼ in. scale or 4 squares = 1 in.
Give students time to complete this in Activity Dimensioning before going on to the next slide.

22. Here They Are Dimensioning Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Here They Are
Notice that the dimension value is all the same, but the dimension is measuring the size of different features. This is NOT duplicating a dimension. Often you will have the same value, but you will dimension different features.