Tolerance Stack-up Analysis Flashcards
7 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 7 Tolerance Stack-up Analysis flashcards as text
What advantage does GD&T cylindrical position tolerance offer over square coordinate tolerancing in a stack-up budget?
Answer: The cylindrical tolerance zone provides approximately 57% more tolerance area than a square zone of the same width
A cylindrical tolerance zone for position has approximately 57% more area than a square coordinate tolerance zone of the same width, effectively increasing the available tolerance budget.
In a tolerance stack-up, what is the 'requirement' being evaluated?
Answer: The minimum clearance or maximum interference condition that must be met for proper function
The requirement is the functional condition that must be satisfied, such as maintaining minimum clearance to prevent interference or ensuring parts assemble correctly.
Which analysis method accepts a small percentage of non-conforming assemblies in exchange for allowing larger individual part tolerances?
Answer: Statistical (RSS) analysis
Statistical RSS analysis accepts a small percentage of assemblies that may fail (typically 0.27% for ±3σ), trading a guaranteed function for larger individual part tolerances.
What generally happens to each individual component tolerance as the number of components in a stack-up increases while the assembly requirement stays fixed?
Answer: Each component must be made to tighter tolerances to maintain the same assembly requirement
As more components are added to a stack-up, each individual part must be made to tighter tolerances if the overall assembly tolerance requirement remains unchanged.
In tolerance stack-up analysis, what is a 'contributing dimension'?
Answer: Any dimension whose variation affects the critical assembly condition being analyzed
A contributing dimension is any dimension whose tolerance directly affects the variation of the critical gap, clearance, or interference being analyzed in the stack-up loop.
What is 'assembly shift' (datum shift) in the context of tolerance stack-up analysis?
Answer: Additional variation allowed when a datum feature departs from its maximum material condition
Assembly shift (datum shift) refers to the additional movement or variation allowed when a datum feature departs from its maximum material condition, creating extra tolerance in the stack.
Which of the following best describes 'allocating tolerances' in a tolerance stack-up study?
Answer: Distributing the total assembly tolerance budget among individual component dimensions
Tolerance allocation is the process of dividing the total permissible assembly variation among the contributing component dimensions based on manufacturing capability and functional criticality.