CDT Geometric Dimensioning & Tolerancing Flashcards

A bilateral tolerance of 1.500 ±0.005 means the dimension may range from:

Answer: 1.495 to 1.505

A bilateral tolerance of ±0.005 applied to 1.500 gives a range of 1.500 − 0.005 = 1.495 to 1.500 + 0.005 = 1.505.

Which symbol in a GD&T feature control frame indicates that the tolerance applies 'regardless of feature size'?

Answer: No modifier symbol (RFS is the default under ASME Y14.5-2009)

Under ASME Y14.5-2009, RFS is the default condition when no modifier is specified; no special symbol is needed to invoke it.

The virtual condition of an external feature (shaft) is calculated as:

Answer: MMC size plus the geometric tolerance

For an external feature (shaft), virtual condition = MMC (largest size) + the applicable geometric tolerance, representing the worst-case boundary for assembly.

On a US drawing, what does the term 'tolerance stack-up' refer to?

Answer: The cumulative effect of multiple tolerances in a chain of dimensions

Tolerance stack-up is the accumulation of individual dimensional tolerances along a chain that determines the total variation at a critical feature.

Perpendicularity as a GD&T control specifies that a surface or axis must be within a tolerance zone oriented at:

Answer: Exactly 90° to the specified datum

Perpendicularity controls the orientation of a surface or axis to be within a tolerance zone that is exactly 90° relative to the referenced datum.

Which measurement tool is most commonly used in the US to verify a cylindricity tolerance on a machined part?

Answer: Coordinate Measuring Machine (CMM)

A CMM is the most capable and commonly used instrument for verifying cylindricity because it can capture three-dimensional surface data across the entire cylinder.