Introduction / Context:
Sectional views expose interior details by cutting through a component. A common question is whether hidden (dashed) lines should appear within a section. The general convention is to omit hidden lines in section views to reduce clutter, because the cut itself reveals interior features that would otherwise be hidden.
Given Data / Assumptions:
- Hidden lines represent features obscured from view.
- Section lining (hatching) indicates cut material.
- Clarity and readability are primary goals in engineering graphics.
Concept / Approach:
In most cases, hidden lines are not shown in the portion of the view that is sectioned. The cut surface and visible outlines make hidden lines unnecessary. Exceptions exist: hidden lines may be used sparingly to represent features that lie beyond the cutting plane and are important for understanding, but this is the exception, not the rule.
Step-by-Step Solution:
Establish the cutting plane and generate the sectional view.Show the cut surfaces with hatch; draw only the visible edges associated with the section.Avoid hidden lines within the sectioned region unless essential to comprehension.If hidden lines are needed, ensure they do not overpower visible outlines and hatch.
Verification / Alternative check:
Compare two versions of the same section: readability almost always improves without unnecessary hidden lines.
Why Other Options Are Wrong:
Correct: Asserting that hidden lines are “typically included” contradicts the usual practice of omitting them in sections.Only shown when scale is small / Always required in every section: Scale does not create a requirement; “always” is not consistent with standards-focused clarity.
Common Pitfalls:
Overusing hidden lines in sections, leading to visual noise.Failing to add an auxiliary or detail view when a special internal feature truly needs emphasis.
Final Answer:
Incorrect
Discussion & Comments