Mechanical Drafting and Design

Specific Competencies and Skills Tested in this Assessment:

Preparing to Draw: Basic Drawing and Dimensioning Skills

• Measure lines, angles, and geometric features 
• Identify drawing views and details 
• Identify assembly drawings, detailed drawings, and other drawings by type 
• Identify revisions and apply engineering change information 
• Identify and create line types 
• Identify and create sketches 
• Complete title block and apply reference information 
• Identify and complete a parts list/bill of materials 
• Select and interpret scale and paper size 
• Identify and operate design tools/instruments (CAD and/or manual) 
• Identify reference charts and tables 

 

Applied Mathematics

• Demonstrate knowledge of mathematical operations
• Demonstrate knowledge of geometry
• Demonstrate knowledge of trigonometry

 

Identify Measurements 

• Identify and read precision measurement tools
• Calculate unit conversion

 

Geometric Construction 

• Draw lines and curved elements 
• Construct perpendicular and parallel lines 
• Construct tangent lines and arcs 
• Construct geometric shapes 
• Identify and construct developments 
• Bisect and divide geometric elements 

 

Multiview Drawings 

• Demonstrate knowledge of multiview drawings 
• Multiview projection (third angle and first angle)
• Differentiate between major surface types (normal, inclined, oblique, cylindrical)
• Identify common part features (fillets, rounds, draft angles, chamfers)

 

Section Views 

• Identify and construct section views 
• Identify ANSI material symbols 
• Apply section rules 

 

Auxiliary Views 

• Identify and construct auxiliary views
• Draw true view, true length lines, and true angles 

 

Dimensioning Skills 

• Locate and describe features
• Demonstrate knowledge of various unit dimensioning systems 
• Identify finished surfaces
• Demonstrate knowledge of tolerances
• Identify and label common mechanical feature notations
• Place local and general notes, including fonts, lettering size, style, etc.   
• Identify geometric dimensioning and tolerancing symbols
• Identify measurements

 

Written Assessment: 

Administration Time: 3 hours   

Number of Questions: 160

 

Areas Covered:

Preparing to Draw: Basic Drawing and Dimensioning Skills: 25%

Applied Mathematics: 7%

Identify Measurements: 4%

Geometric Construction: 13%

Engineering Drawings: 6%

Multi view Drawings: 10%

Section Views: 9%

Auxiliary Views: 4%

Dimensioning Skills: 22%

 

Sample Questions: 

What drawing method is used to illustrate, on a magnified scale, a view of an object which includes dimensions and clarification information specific to the object?  

1. detail drawing 

1. perspective drawing 
2. oblique drawing 
3. isometric drawing 

 

An octagon has how many sides?  

1. 6 
2. 8 
3. 9 
4. 12 

 

A key feature of an exploded assembly drawing is its arrangement

1. by two organizational systems
2. by vertical placement
3. as a spatial relationship of parts
4. as parts ordered by size

 

Current drafting practices or standards are established by 

1. HOSA 
2. ANSI/ASME 
3. ASA 
4. OSHA  

 

When specifying and identifying threads, what does the underlined number in 1/2  – 13UNC-2A represent?  

1. nominal diameter 
2. class of fit 
3. threads per inch 
4. size of thread in millimeters 

 

What is the most important rule in freehand sketching?

1. Never sketch in color.
2. Keep the sketch in proportion.
3. Always use the squares method.
4. Always use drafting tools.

 

An isometric and oblique are examples of _____ drawings.

1. realistic
2. pictorial
3. common
4. cavalier

 

There are _____ normal viewing planes to view an object.  

1. 2
2. 4
3. 6
4. 8

 

Auxiliary views are always projected from an edge of a surface that is 

1. hidden from view
2. horizontal to the viewing plane
3. nonparallel to a principal view
4. perpendicular to the viewing plane

 

How many degrees are in a straight line?

1. 160 degrees
2. 180 degrees
3. 200 degrees
4. 360 degrees

Performance Assessment:

Administration Time: 3 hours 

Number of Jobs: 4 

 

Areas Covered:

21% Auxiliary Views 

Use of tools or computer program, complete drawing – top view, complete drawing – front view, complete drawing – partial auxiliary view, line quality, and time to complete Job 1.  

 

36% Drawing Completion and Dimensioning 

Use of tools or computer program, complete drawing – top view, complete drawing – front view, complete drawing – right side view, line quality, placement of dimensions, tolerance of feature sizes and locations, and time to complete Job 2.  

 

19% Pattern Development 

Use of tools or computer program, use of construction techniques, solution, line quality, and time to complete Job 3.   

 

24% Section Drawing 

Use of tools or computer program, complete drawing – front view, complete drawing – full section view, section hatch pattern, line quality, and time to complete Job 4.  

 

   

Sample Job:

Auxiliary Views       

Maximum Time: 35 minutes 

Participant Activity:   CAD or Manual Options:  Using the graphic provided, the participant will draw a top, front, and partial auxiliary view showing inclined, true size and shape on an A-size drawing sheet.  Manual Option only – showing construction line sis optional and will not be graded.