For a cylindrical mechanical part that is symmetric, which section type often allows the drafter to communicate both interior and exterior details using only one primary view? Select the section that commonly replaces the need for an additional view.

Introduction / Context:
Symmetric cylindrical parts (bushings, hubs, bearings) often have interior features (holes, bores, keyways) aligned with the axis. Presenting both outside profile and inside details in one clean view improves readability and saves sheet space.

Given Data / Assumptions:

• The part is symmetric about an axis (typical cylinder).
• The goal is to show interior and exterior at once.
• We compare half, full, revolved, and broken-out section techniques.

Concept / Approach:

A half section removes a quarter of the object by a straight cutting plane through the axis. The resulting view shows one half in section (interior features hatched) and the other half in external view. For cylindrical symmetry, this often suffices as the sole primary view.

Step-by-Step Solution:

Verification / Alternative check:

Engineering graphics texts recommend half sections specifically for symmetric objects because they simultaneously reveal inside and outside geometry.

Why Other Options Are Wrong:

Whole (full) section shows the entire object cut; still might require additional external context.

Revolved section depicts a local cross-section rotated into the view; not a full primary view substitute.

Broken-out section exposes only a small region; not comprehensive enough to replace other views.

Common Pitfalls:

Forgetting to omit hidden lines in the sectioned half unless standards call for them; hatching rules must be followed.

Final Answer:

half