Definitions Flashcards
A worst case boundary generated by the smallest feature (MMC for an internal feature, and LMC for an external feature), minus the stated geometric tolerance in any additional geometric tolerance (if applicable), resulting from the features departure from its specified material condition.
Inner boundary
The limit defined by tolerance or combination of tolerances, that exists on or inside the material of a feature (S).
Least Material Boundary(LMB)
The limit defined by a tolerance or combination of tolerances that exists on, or outside the material of a feature.
Maximum Material Boundary(MMB)
The worst case boundary generated by the largest feature (LM C, for an internal feature and MMC for an external feature), plus the stated geometric tolerance and any additional geometric tolerance (if applicable), resulting from the features departure from its specific material condition.
Outer Boundary
A single surface of compound curvature, or a collection of other features that constrains up to six degrees of freedom.
Complex Feature
A theoretically exact point axis, line plane, or combination thereof, derived from the theoretical datum feature simulator.
Datum
The axis of a datum feature simulator established from the datum feature.
Datum Axis
The center plain of a datum feature simulator established from the datum feature.
Datum Center Plane
A feature that is identified with either a datum feature symbol, or a datum target symbol.
Datum Feature
Encompasses, two types, theoretical and physical.
Datum feature simulator
The theoretically, perfect boundary used to establish a datum from a specified datum feature.
Datum Feature Simulator(Theoretical)
The physical boundary used to establish a simulated datum from a specified datum feature.
Datum Feature Simulator(Physical)
A point axis line or plane (or combination thereof), coincident with or derived from processing or inspection equipment, such as the following simulators: a surface plate, a gauge surface, a mandrel, or a mathematical equation.
Simulated Datum
A numerical value(S) or a mathematical expression, in appropriate units of measure used to define the form size, orientation, or location of a part or feature.
Dimension
A theoretically exact dimension
Basic Dimension
A dimension usually without a tolerance that is used for informational purposes only.
Reference Dimension
This envelope is outside the material. A similar perfect feature (S) counterpart of smallest size that can be contracted about an external feature(S so that it coincides with the surface (S) at the highest points.
Actual Mating Envelope
A similar perfect feature (S) counterpart expanded within an internal feature (S) or contracted about an external feature (S) and not constrained to any datum(s).
Unrelated Actual Mating Envelope
A similar perfect feature counterpart expanded within an internal feature (S) or contracted about an external feature (S) while constrained, either in orientation or location or both to the applicable datum(s).
Related Actual Mating Envelope
This envelope is within the material. A similar perfect feature(S) counterpart of largest size that can be expanded within an external feature (S) or smallest size that can be contracted about an internal feature (S) so that it coincides with the surface (S) at the lowest points.
Actual Minimum Material Envelope
A similar perfect feature (S) counterpart contracted about an internal feature (S) or expanded within an external feature S) and not constrained to any datum reference frame.
Unrelated Actual Minimum Material Envelope
A similar perfect feature (S) counterpart contracted about an internal feature (S) or expanded within an external feature (S) well, constrained in either orientation or location or both to the applicable datum(s).
Related Actual Minimum Material Envelope
A physical portion of a part such as a surface, pinhole or slot, or its representation on drawings, models, or digital data files.
Feature
The axis of the unrelated actual mating envelope of a feature.
Feature Axis
The center plane of the unrelated actual mating envelope of a feature.
Center Plane of Feature
An imperfect (abstract) plain formed by the centerpoint of all line segments bounded by the feature. These line segments are normal (perpendicular) to the center plane of the unrelated actual mating envelope.
Derived Median Plane
An imperfect (abstract) line formed by the centerpoint of all cross-sections of the feature. These cross-sections are normal (perpendicular) to the axis of the unrelated actual mating envelope.
Derived Median Line
Encompasses two types: regular and irregular.
Feature of Size
One cylindrical, or spherical surface, a circular element, and a set of two opposed parallel elements, or opposed parallel surfaces, each of which is associated with a directly toleranced dimension.
Regular Feature of Size
The two types of irregular features of size are as follows:
(A) a directly tolerance feature or collection of features that may contain or be contained by an actual mating envelope that is a sphere cylinder or pair of parallel planes.
(B) a directly tolerance feature or collection of features that may contain or be contained by an actual mating envelope, other than a sphere cylinder or pair of parallel planes
Irregular Feature of Size
The tolerance zone framework (S) that controls the basic relationship between the features, and a pattern with that framework, constrained in rotational degrees of freedom relative to any referenced datum features.
Feature-Relating Tolerance Zone Framework (FRTZF)
The condition of a part free of applied forces.
Free State
The condition in which a feature of size contains the least amount of material within the stated limits of size.
Least Material Condition(LMC)
The condition in which a feature of size contains the maximum amount of material within the state of limits of size.
Maximum Material Condition(MMC)
Two or more features or features of size to a locational geometric tolerance is applied, and are grouped by one of the following method: NX, n coaxial holes, all over, a left arrow right arrow be, n surfaces, simultaneous requirements, or indicated.
Pattern
The tolerance zone framework that controls the basic relationship between the features in a pattern with that framework, constrained in translational and rotational degrees of freedom relative to the referenced datum features.
Pattern Locating Tolerance Zone Framework(PLTZF)
A plane that contacts the highpoints of the specified feature surface.
Tangent Plane
Indicates that a geometric tolerance applies at any increment of size of the actual mating envelope of the feature of size.
Regardless of feature size(RFS)
Indicates that a datum feature simulator progresses from MMB toward LMB, until it makes maximum contact with the extremities of a feature (S).
Regardless of material boundary (RMB)
The application of force (S) to a part to simulate its assembly or functional condition, resulting in possible distortion of a part from its free state condition.
Restraint
The single worst case boundary generated by the collective effects of a feature of sizes, specified MMC or LMC, the geometric tolerance for that material condition, the size tolerance, and the additional geometric tolerance, derived from the features departure from its specified material condition.
Resultant condition
The measured value of any individual distance at any cross-section of a feature size.
Actual local size
Specified maximum and minimum sizes.
Limits of size
The designation used for purposes of general identification.
Nominal size
The total amount a specific dimension is permitted to vary. The tolerance is the difference between the maximum and the minimum limits.
Tolerance
A tolerance in which variation is permitted in both directions from the specified dimension.
Bilateral tolerance
The general term applied to the category of tolerance is used to control size form, profile, orientation, location, and run out.
Geometric tolerance
A tolerance in which variation is permitted in one direction from the specified dimension.
Unilateral tolerance
The theoretically exact location of a feature size, as established by basic dimensions.
True position
A constant boundary generated by the collective effects of a considered feature of sizes specified MMC or LMC and the geometric tolerance for that material condition
Virtual condition
