Precedence when lines coincide: If a cutting plane line coincides with a centerline, which line type takes precedence on the drawing?

Introduction / Context:
Drawings use multiple symbolic line types to convey information. Cutting plane lines indicate where a section is taken and are crucial to interpreting the sectioned view and direction of sight. Centerlines mark axes of symmetry or hole centers. When two line types would occupy the same location, precedence determines which is drawn.

Given Data / Assumptions:

• A cutting plane coincides exactly with a centerline (common for symmetric parts).
• Standard line weights/patterns are used: cutting plane lines are heavier phantom lines with arrows; centerlines are thin chain lines.
• Clarity for section reference is paramount.

Concept / Approach:
Because the cutting plane defines a specific sectional view and must be referenced by labels/arrows, its visibility is essential. Centerlines are helpful but secondary when competing at the same location. Therefore, the cutting plane line takes precedence, ensuring readers can find and follow the section.

Step-by-Step Solution:

Verification / Alternative check:
Review standard examples: symmetric shafts sectioned along the axis typically show only the cutting plane line along the axis; centerline appears in areas away from the overlap.

Why Other Options Are Wrong:

Common Pitfalls:
Leaving both lines with similar weights creates a confusing “double line”; omitting arrows on the cutting plane line, which are required to indicate viewing direction.

Final Answer:
Cutting plane line takes precedence