Technical Drawings Flashcards
What are the 3 types of technical drawings?
1 orthographic
2 pictorial
3 schematic
What are the 2 types of orthographic drawings?
- First angle orthographic
- Third angle orthographic
What are the 3 types of pictorial drawings?
- Isometric
- Oblique
- Perspective
In orthographic what angle are objects being drawn?
90 degrees
What are the 3 elevations most common in orthographic drawings?
- Front
- Side
- Plan (top or bottom)
In isometric drawings all lines are drawn to what angle?
30 degrees to the horizontal
In oblique drawings what angle is the face drawn?
90 degrees
Other than the face what angle are the other sides drawn to in oblique?
45 degrees typically
What lines show the surfaces and features of the object that are not seen in the chosen view?
Hidden lines
What do hidden lines look like?
Thin dotted line
What line is used to shorten the view of long uniform sections?
Break line
What can break lines look like? (2)
- (Long) thin jagged or lightening bolt line
- (Short) thick wavy line
What are the lines that indicate the visible outline of an object called?
Object lines
What do object lines look like?
Thick, dark
What do centre lines look like? (2)
- Long thin dash lines
- Very thin straight lines
What are extension lines?
Lines which extend the object lines out to a convenient spacing
What are the lines that indicate the distance between the extension lines called?
Dimension lines
What are the two methods to dimensioning?
- Aligned
- Unidirectional
What view starts with the front orthographic view and projects the other sides off at an angle?
Oblique
What line terminates with an arrowhead and touches the extension lines?
Dimension lines
What are the two most common pictorial drawings?
- Oblique
- Isometric
In orthographic projections, the objects being viewed are at ________ degrees to each other
90
What part of a dimension is the total permissible variation in its size?
Tolerance
What form of tolerance does 62 +/- 0.002 represent?
Bilateral
What view starts with the front orthographic view and projects the other side off at an angle?
Oblique
What section of the drawing do you find the engineers name?
Title block
What’s the minimum shaft size of a drawing indicates 23.000” +/- 0.005
22.995
How is the front view of a component chosen?
To provide the most detail
On a 1:5 scale 12 inches on the drawing would equal what in feet?
5 feet
A physical measurement of a fit is
A tolerance
Your fit refers to what?
Allowance
If an allowance is a negative number it is what type of a fit?
A clearance fit
Allowance refers to how many parts?
2
Tolerance refers to how many parts?
1
