Introduction / Context:
Line weights must be legible at the intended sheet size and reproduction method. The claim that ASME Y14.2M mandates a fixed 0.8 mm thickness for visible lines oversimplifies the standard. In practice, standards recommend relative line-weight hierarchies and typical ranges, not a single value for all cases.
Given Data / Assumptions:
- Different sheet sizes and scales demand different practical line thicknesses.
- Standards emphasize clarity, contrast, and line-type recognition.
- Companies often define approved thickness sets (e.g., thick/medium/thin) within templates.
Concept / Approach:
ASME and ISO focus on line type definitions and relative precedence rather than one absolute thickness. While a visible line is thicker than hidden and centerlines, the exact numeric thickness can vary (for example, many organizations use around 0.5–0.7 mm for visible lines on common sizes). Therefore, asserting 0.8 mm as a universal requirement is incorrect.
Step-by-Step Solution:
Select a line-weight set (thick, thin) appropriate for sheet size and plotter.Ensure visible lines remain clearly heavier than hidden and centerlines.Validate output with a plotted sample to confirm readability after scaling or copying.Document chosen values in CAD standards so all drawings remain consistent.
Verification / Alternative check:
Compare multiple plots at different scales; legibility, not a fixed number, determines suitability.
Why Other Options Are Wrong:
Correct: Claiming a universal 0.8 mm prescriptive value is inaccurate.Applies only to A-size sheets / Applies only to color plots: The statement is not about sheet size or color; it is about a supposed fixed standard thickness.
Common Pitfalls:
Using one thickness across all line types, destroying visual hierarchy.Failing to test printed output, leading to centerlines that look like hidden lines.
Final Answer:
Incorrect
Discussion & Comments