Tolerancing practice on angles: Have unilateral tolerances (all variation to one side of the target) traditionally been applied to angular dimensions, or are angles usually specified with symmetric (bilateral) tolerances?

Introduction / Context:
Tolerance notation communicates acceptable variation. For linear and angular dimensions, the two common styles are bilateral (±) and unilateral (all plus or all minus). This question checks whether unilateral tolerances are the traditional norm for angles.

Given Data / Assumptions:

• Angles on drawings are commonly given with bilateral limits, for example 45° ± 1°.
• Unilateral angular limits are possible but less typical, reserved for special functional cases.
• Geometric controls (e.g., perpendicularity) may further refine angular behavior without using direct angular size tolerances.

Concept / Approach:
Historically and practically, the symmetric nature of many angular functions makes ± tolerances convenient and readable. Unilateral tolerances are used when functional requirements demand only one-directional deviation (e.g., to ensure clearance in one direction). Therefore, asserting that unilateral tolerances have “traditionally been given on angles” does not reflect common practice.

Step-by-Step Solution:
Identify typical notation: angles listed with ± tolerance in general notes or next to the angle.Recognize unilateral as an exception used for special fits or functional needs.Compare with the statement claiming unilateral is the traditional default.Conclude the statement is incorrect.

Verification / Alternative check:
Survey sample drawing templates: general tolerance blocks often state “Angular ±X°,” confirming bilateral dominance.

Why Other Options Are Wrong:
“Correct” misstates convention. Claims about countersinks, geometric control, or reference angles do not overturn the general norm.

Common Pitfalls:
Assuming one-sided allowance practices for linear features directly translate to angles; conflating geometric controls with size tolerances.

Final Answer:
Incorrect