GD&T ASME Y14.5 Standards and Drawing Interpretation Flashcards
6 cards from real GD&T practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 GD&T ASME Y14.5 Standards and Drawing Interpretation flashcards as text
What does the Free State modifier (encircled F) in a feature control frame specify?
Answer: The geometric tolerance applies to the part in its unrestrained, free (unclamped) condition
The free state modifier requires that the specified geometric tolerance be met without any restraining fixture, which is critical for non-rigid or flexible parts.
What is 'true position' in GD&T?
Answer: The theoretically exact location of a feature, defined by basic dimensions from the datum reference frame
True position is the perfect, theoretically exact location of a feature, established by basic dimensions, from which the positional tolerance zone is centered.
How is a projected tolerance zone indicated in a feature control frame?
Answer: With an encircled P symbol followed by the minimum projection height value
The encircled P (Ⓟ) modifier followed by the projection height extends the tolerance zone above the part surface to control the orientation of inserted fasteners or studs.
What is the functional significance of datum precedence order (primary, secondary, tertiary)?
Answer: It determines which degrees of freedom each datum constrains, in priority order, during measurement and assembly
Primary datum constrains three degrees of freedom, secondary constrains two more, and tertiary constrains the last one — order matters for repeatability of measurement.
When multiple geometric controls are applied to the same feature (e.g., both flatness and profile), how must the part conform?
Answer: It must satisfy all controls simultaneously — none overrides another
All geometric tolerances applied to a feature are independent requirements; the part must comply with every callout at the same time.
When does a title-block general tolerance apply to a dimension on an engineering drawing?
Answer: When the dimension has no explicit tolerance callout and is not a basic dimension
Title-block general tolerances provide a default for any dimension that lacks its own explicit tolerance; basic dimensions (boxed) are excluded because their tolerance is defined by the associated feature control frame.