1. UNIVERSITY OF PUERTO RICO AT HUMACO
DEPARTMENT OF PHYSICS
ENGINEERING GRAPHICS I
Traditional tools
Dr. Walter López Moreno 1

2. Introduction to Engineering Graphics
Importance of technical graphics
Traditional engineering design & Changes in the engineering design process
Technical drawing tools
Standards
ANSI standard sheet sizes
Basics: Line weight & pencil grades
Alphabet of lines

3. Importance of technical graphics
" the engineer, scientist, or technician who is ignorant of or deficient in the principal mode of expression (that is, the universal graphic language) in his or her technical field is professionally illiterate."    
- Page 8. Principles of Technical Drawing
This statement summarizes the importance of technical graphics.

4. Importance of technical graphics
Technical drawings: A language used in the design process for communicating, solving problems, quickly and accurately visualizing objects, and conducting analysis
A graphical representation of objects and structures and is done using freehand, mechanical, or computer methods
-The drafting and design phases comprise more than 52 percent of the engineering process.
Users of engineering and technical graphics in industry

5. From traditional “linear” design process to new“concurrent” design process
Traditional: A linear, segmented activity involving problem identification, preliminary ideas, design refinements, analysis, optimization, and documentation
Concurrent: A team activity involving coordination of the technical and non-technical functions of design and manufacturing within a business
The CAD database becomes a communication medium.

6. Samples of drawing conventions and standards

7. Architectural Drawing
Lewis Park (Second Floor) downstairs of 2, 3 and 4 bedroom

8. Manual drafting tools for technical drawing
Mechanical pencils: 0.7 and 0.5 mm, or 0.5 and 0.3 mm combinations; Pencil grades – HB and H, or F and 2H combinations)
Compass and one divider
One set of 45- and 30/60-degree triangles
Scales (one English unit and one Metric unit)
Irregular curve (French curve)
Protractor
One good eraser

9. Use of drafting tools – a few examples

10. Standards Organizations involved in developing the standards for
technical drawings:
ANSI (American National Standards Institute)
ASEE (American Society for Engineering Education)
SAE (Society of Automotive Engineers)
ASME (American Society of Mechanical Engineers)
ISO (International Standards Organization)
American National Standard Drafting Manual
ANSI is the governing body that sets the standards used for engineering and technical drawings
ANSI standards are periodically revised to reflect the changing needs of the industry and technology
The Y series of ANSI standards are the ones most important for technical drawing.
ISO is made up of a group of standards institutes from 145 different countries

11. Some Important ANSI standards
ANSI Y14.1 (1980) Drawing Sheet Size and Format.
ANSI Y14.2M (1979) Line Conventions and Lettering.
ANSI Y14.3 (1975) Multiview and Sectional View Drawings
ANSI Y14.5M ( ) Dimensioning and Tolerancing.
ANSI Y14.6 (1978) Screw Thread Representation
ANSI Y14.6aM (1981) Screw Thread Representation (Metric Supplement)
ANSI Y & Y (1978) Gear Drawing Standards

12. ANSI Standard Sheet Sizes & typical title block layouts

13. Pencil grades and Line weight
Remember that Accuracy, Neatness, and Speed count in technical drawing

14. Alphabet of lines (1)

15. Alphabet of lines (2)