Introduction / Context:
Consistent line conventions enable any trained reader to understand drawings quickly. The visible (object) line is foundational: it depicts edges actually seen from the viewpoint of the given orthographic or pictorial view, and it is typically the boldest line on the sheet to establish visual precedence.
Given Data / Assumptions:
- Visible lines use a continuous pattern and heavier weight.
- Hidden lines use short dashes; centerlines use alternating long/short dashes of lighter weight.
- Clarity depends on differentiating these patterns and weights.
Concept / Approach:
By definition, a visible line indicates an edge or contour that is directly observable in the chosen view. Using a continuous thick line for these edges ensures they stand out against hidden and centerlines. This visual hierarchy helps readers prioritize the geometry that actually defines the part’s silhouette in each view.
Step-by-Step Solution:
Determine which edges are visible from the view direction.Draw those edges with a continuous thick line to denote visibility.Use hidden and centerlines where appropriate, maintaining line precedence rules.Confirm readability on the intended plot size and medium.
Verification / Alternative check:
Cross-check with an isometric or 3D model; edges visible in that view should correspond to visible lines in the drawing.
Why Other Options Are Wrong:
Incorrect: Contradicts the standard definition of visible lines.Used only on isometric views / Reserved solely for center axes: Visible lines are used in orthographic and pictorial views; center axes use centerlines, not visible lines.
Common Pitfalls:
Allowing visible lines to be too thin, making them indistinguishable from hidden lines.Using visible lines where hidden lines should be used, confusing depth relationships.
Final Answer:
Correct
Discussion & Comments