Tolerancing Questions

• This is the measured size of a finished part:
• This practice considers an individual part's dimensions and tolerances and that part's relation to its related parts:
• This is the term for the range of tightness or looseness resulting from the allowances and tolerances in mating parts:
• This means that a feature of a finished product contains the maximum amount of material permitted by the toleranced dimensions for that feature:
• This is the theoretically exact size from which limits of size are determined:
• Acceptable parts must not extend beyond this:
• When lines intersect on a drawing at angles of this many degrees, it is customary not to dimension the angle:
• Unilateral tolerances have traditionally been given on angles.
• Allowance is the maximum clearance or minimum interference specified to achieve a fit between two mating parts.
• Implied 90 degree angles typically have different general tolerances applied to them than other angles covered by a general note.
• Nominal size is used for general identification and is usually expressed in decimals.
• Tolerances of form and position are typically not used to control straightness.
• Defining the datum reference frame is necessary to apply GDT principles.
• Datum surfaces and features are used as references to control other features.
• Geometric dimensioning and tolerancing can simplify the inspection process.
• Specific tolerances are based on the part's function and fit.
• Tolerance is the total amount a specific dimension is permitted to vary.
• Increased precision makes parts less expensive to manufacture.
• The ISO has its own system of preferred metric limits and fits.
• Geometric tolerances state the maximum allowable variations of a form or its position from the perfect geometry implied in the drawing.