Chapter 7 Sectional Views

Suggested Answers for Review Questions

1. What does the cutting-plane line represent?

The cutting-plane line represents edge view of the cutting plane, in order to show the inside features of the object. The arrows indicate the viewing direction.

2. Sketch the section-line patterns for 10 different materials.

To the satisfaction of the instructor, compared to Fig 7.6.

3. List seven different types of sections and an example of when each is drawn.

Full section, Half section, Broken-out section, Revolved sections, Removed sections, Offset sections, Aligned sections.

Instructor evaluation of sketches.

4. Which sectional views are used to replace an existing primary view? Which sectional views are used in addition to the primary views?

Most commonly, Full sections, Half sections, and Aligned sections replace a primary view. A Revolved section may also remove the need for a primary view

Usually, Removed sections and Offset sections do not replace a primary view.

5. How much of an object is imagined to be cut away in a half section?

A quarter of the object (1/4th)

6. What type of line is used to show the boundary of a broken-out section?

A short-break line

7. Why are hidden lines generally omitted in a sectional view?

The purpose of hidden lines is to show hidden features. If a section exposes the hidden features, no hidden lines are required.

8. Why are some symmetrical features, like spokes and webs, revolved in the sectional view?

The features are imagined to be revolved until they line up vertically and are projected from that position to insure clarity is improved. If clarity is not improved, then the feature is not rotated.

9. Why is a rib outlined with object lines and not filled with section lining?

To avoid a false impression of thickness and solidity.