Dimension text orientation: Should all dimension values and notes be lettered horizontally so they can be read from the bottom of the sheet (unidirectional practice)?

Introduction / Context:Two text-orientation systems exist for dimensions: unidirectional and aligned. Unidirectional places all dimension text horizontally, readable from the bottom of the sheet. This is prevalent in many organizations because it improves consistency and speeds reading, especially in CAD environments and digital viewing.

Given Data / Assumptions:

• The drawing follows a unidirectional convention unless otherwise specified.
• Clarity and speed of interpretation are priorities.
• Dimensions should not require rotating the sheet to read.

Concept / Approach:With unidirectional dimensioning, text and numerals are always horizontal. Extension and dimension lines may be at various angles, but the numbers stay upright. This reduces reader fatigue and errors, particularly in large assemblies. Some industries use aligned text, but unidirectional remains a widely accepted default in modern practice.

Step-by-Step Solution:

Verification / Alternative check:Open any recent CAD template from major CAD systems; default styles typically use unidirectional text, confirming the practice.

Why Other Options Are Wrong:

Common Pitfalls:Mixing aligned and unidirectional on the same drawing; allowing auto-rotated dimensions to slip through QA, causing readability issues.

Final Answer:Correct