Introduction / Context:
Drawings are legal and manufacturing documents. While dimensions and geometry define size and shape, line weight and line type communicate visibility, hidden features, axes, and cutting actions. Ignoring them risks misinterpretation, production errors, and inspection disputes.
Given Data / Assumptions:
- Visible objects use continuous thick lines; hidden features use dashed lines.
- Centerlines, cutting planes, break lines, and phantom lines each have specific patterns.
- Standards (ASME/ISO) specify precedence and typical thickness relationships.
Concept / Approach:
Line conventions are part of a shared visual language. Correct line weight hierarchy ensures that visible outlines dominate, hidden edges are legible but subordinate, and centerlines remain distinguishable. This hierarchy allows quick and consistent reading across teams and suppliers, independent of CAD system or plotting device.
Step-by-Step Solution:
Assign line types and thicknesses according to standards and company CAD templates.Use layers or styles so visible, hidden, and centerlines are clearly differentiated.Check plotted output to confirm legibility at intended sheet sizes.Apply line precedence: visible lines override hidden; hidden override centerlines when coincident.
Verification / Alternative check:
Print a sample in grayscale: the correct hierarchy should remain readable without color.
Why Other Options Are Wrong:
Correct: Saying line weight/type are unimportant is false; they are essential to clarity.Matters only for 3D-printed parts / Only affects color plots: Proper linework is critical for any fabrication or inspection process, regardless of technology or color.
Common Pitfalls:
Using identical thickness for all lines, flattening the visual hierarchy.Ignoring output device characteristics, causing centerlines to appear as hidden lines.
Final Answer:
Incorrect
Discussion & Comments