Auxiliary views in engineering graphics — In most cases, should hidden lines be omitted from auxiliary views to improve clarity unless they communicate essential interior features?

Introduction / Context:
Auxiliary views in technical drawing are created to show the true size and shape of features that are inclined or skewed to the principal projection planes. Deciding whether to include hidden lines affects readability, interpretation time, and risk of miscommunication during manufacturing and inspection.

Given Data / Assumptions:

• The statement claims that hidden lines are generally omitted in auxiliary views.
• We assume standard mechanical drafting practices and conventions used in industry training.
• Objective: produce views that are quick to read while preserving necessary detail.

Concept / Approach:
Hidden lines indicate features obscured from the observer in a given view. While valid, they can clutter drawings. The common practice for auxiliary views is to omit nonessential hidden lines to emphasize the geometry being clarified (e.g., true shape of an inclined face). When interior definition is crucial, a sectioned auxiliary view or selectively added hidden lines are used instead.

Step-by-Step Solution:
1) Identify purpose of the auxiliary view: reveal true size/shape of an inclined feature.2) Evaluate impact of hidden lines: many short dashes obscure the very area being clarified.3) Apply convention: omit hidden lines unless they convey essential information.4) Prefer section views when interior detail must be communicated clearly.

Verification / Alternative check:
Compare two auxiliary views of a bracket: one with dense hidden lines and one with only visible edges. Reviewers typically read the simplified view faster, while a sectioned auxiliary conveys interiors more clearly than hidden lines alone.

Why Other Options Are Wrong:

• Incorrect: Contradicts the usual clarity-first convention.
• Only in primary auxiliary views: The principle applies to both primary and secondary auxiliaries.
• Only when the view is sectioned: Omission is not limited to sectioned cases.
• Applicable to CAD but not to hand sketches: The convention is tool-agnostic.

Common Pitfalls:
Including every possible hidden edge; failing to switch to a sectioned auxiliary when interiors matter; mixing too many line types and weights in a small area; not referencing a separate detailed view for complex interiors.

Final Answer:
Correct