ASME

The condition of a surface, feature’s center plane, or feature’s axis at any specified angle from a datum plane or datum axis.

Reference: ASME Y14.5-2009, par. 6.3.1

ISO

A geometrical tolerance that controls the orientation of the surface, median plane, or median line relative to one or more datums.

Reference: ISO 1101:2012, Clause 18.11

ASME

ISO

Dimensions, tolerances, notes, text, or symbols visible without any manual or external manipulation.

Dimension(s), tolerance(s), note(s), text or symbol(s) visible without any manual or external manipulation.

Reference: ASME Y14.41-2012, par. 3.1

Reference: ISO 10209:2012, Clause 9.1

Common

An entity in the CAD model that contains an annotation, such as a dimension or a geometric tolerance.

Reference: None

ASME

ISO

A model in which the product described is an assembly of two or more items.

A model in which the product described is an assembly of two or more items.

Reference: ASME Y14.41, par. 3.3

Reference: ISO 10209:2012, Clause 9.3

ISO

An ideal feature established from a non-ideal surface model or from a real feature through an association operation (can be established from a derived or an integral feature).

Reference: ISO 17450-1:2011; Clause 3.3.8

ASME

A theoretically exact dimension.

Reference: ASME Y14.5-2009, par. 1.3.23

ASME

Where MMC or LMC is specified for a geometric tolerance, an increase in the tolerance equal to the departure of the feature of size from the specified material condition.

Reference: ASME Y14.5-2009, par. 2.8.2 and 2.8.4

ISO

The selected parts of a computer-aided design (CAD) model as presented on screen or paper.

Reference: ISO 10209:2012, Clause 11.23 (from ISO 13567-1:1998)

Common

An element that defines some aspect of the geometry of a CAD model, such as an extruded cut or a hole. Note that this differs from feature as defined in ASME Y14.5 or geometrical feature as defined in ISO 17450.

Reference: None

Common

A common-language term used interchangeably with the term Model. ‘CAD’ is an abbreviation for Computer-Aided Design.

Reference: None

ASME

ISO

A geometric tolerance that provides control of circular elements of a surface. The tolerance is applied independently at each circular measuring position as the part is rotated the full angular extent of the surface about the simulated datum axis.

A geometrical tolerance that specifies that the extracted line...

Reference: ASME Y14.5-2009, par. 9.4.1

Reference: ISO 1101:2012, Clause 18.15

ASME

The condition of a surface where,

Reference: ASME Y14.5-2009, par. 5.4.3

ISO

A geometrical tolerance that controls a median line of a feature to be within a cylindrical tolerance zone, centered on a datum axis.

Reference: ISO 1101:2012, Clause 18.13.2

ISO

Where MMR or LMR is indicated, the combination of two independent requirements (e.g., diameter tolerance and position tolerance) into a single requirement that more accurately simulates the intended function of the workpiece.

Reference: ISO 2692:2006

ASME

ISO

A datum established from two or more datum features considered simultaneously.

A datum established from two or more datum features considered simultaneously.

Reference: None

Reference: ISO 5459:2011, Clause 3.9

ISO

A modifying symbol that follows the tolerance in the tolerance frame and indicates that a single tolerance zone is applied to several separate features.

Reference: ISO 1101:2012, Clause 8.5

ASME

The condition where the median points of all diametrically opposed elements of a surface of revolution (or median points of correspondingly located elements of two or more radially disposed features) are congruent with a datum axis (or center point).

Reference: ASME Y14.5-2009, fig. 1-37

ISO

A geometrical tolerance that controls the center point of a feature at any cross-section to be within a circular tolerance zone, centered on a datum axis.

Reference: ISO 1101:2012, Clause 18.13.1

ASME

ISO

A cylindrical flat-bottomed hole that enlarges another coaxial hole that is typically used when a fastener is required to sit flush with or below the level of a workpiece's surface.

A cylindrical flat-bottomed hole that enlarges another coaxial hole that is typically used when a fastener is required to sit flush with or below the level of a workpiece's surface.

Reference: ASME Y14.5-2009, fig. 1-37

Reference: None

ASME

The condition of a surface of revolution in which all points of the surface are equidistant from a common axis.

Reference: ASME Y14.5-2009, par. 5.4.4

ISO

A geometrical tolerance that specifies that the extracted cylindrical surface shall be contained between two coaxial cylinders with a difference in radii that is equal to the indicated tolerance value.

Reference: ISO 1101:2012, Clause 18.4

ASME

ISO

A theoretically exact point, line, plane, or combination thereof derived from the theoretical datum feature simulator.

One or more situation features of one or more features associated with one or more real integral features selected to define the location or orientation, or both, of a tolerance zone or an ideal feature representing for instance a virtual condition.

Reference: ASME Y14.5-2009, par. 1.3.13

Reference: ISO 5459:2011, Clause 3.4

ASME

ISO

The axis of a datum feature simulator established from the datum feature.

A datum that is a theoretically exact straight line.

Reference: ASME Y14.5-2009, par. 1.3.14

Reference: ISO 5459:2011, Clause 3.4

ASME

ISO

A feature that is identified with either a datum feature symbol or a datum target symbol.

A real (not ideal) integral feature used for establishing a datum

Reference: ASME Y14.5-2009, par. 1.3.16

Reference: ISO 5459:2011, Clause 3.2

ISO

The allowable movement or looseness between the part datum feature and the simulated datum feature.

Reference: None

ASME

The allowable shift/displacement of a datum feature from the boundary established by the datum feature simulator.

Reference: ASME Y14.5-2009, par. 4.11.9

ASME

There are two types datum feature simulators:

Reference: ASME Y14.5-2009, par. 1.3.17

ASME

ISO

The plane of a datum feature simulator established from the datum feature

A datum that is a theoretically exact plane.

Reference: None

Reference: ISO 5459:2011, Clause 3.4

ASME

ISO

A set of three mutually perpendicular planes that constitutes a reference frame for dimensioning and tolerancing.

This is an ASME term that is similar to the ISO term Datum System. The ASME term is used throughout the GD&T Advisor application and documentation, but refers to a datum system when in the context of ISO GPS.

See Datum System.

Reference: ASME Y14.5-2009, par. 4.7

Reference: ISO 5459:2011, Clause 3.10

ISO

A set of two or more situation features established in a specific order from two or more datum features.

Reference: ISO 5459:2011, Clause 3.10

ASME

ISO

The designated points, lines, or areas that are used in establishing a datum.

A portion of a datum feature which can nominally be a point, a line segment, or an area.

Reference: ASME Y14.5-2009, par. 4.24.2

Reference: ISO 5459:2011, Clause 3.11

Common

A translational or rotational movement of a part relative to the axes of a coordinate system. All parts have six degrees of freedom, three translational and three rotational.

Reference: None

Common

The constrainable degrees of freedom of a feature, based on symmetry.

Reference: None

ASME

ISO

The portion of the data set that contains model geometry and supplemental geometry.

The portion of the data set that contains model and supplemental geometry.

Reference: ASME Y14.41-2012, par. 3.12

Reference: ISO 10209:2012, Clause 9.8

ASME

ISO

A numerical value or mathematical expression in appropriate units of measure used to define form, size, orientation, or location of a part or feature.

The distance between two features or the size of a feature of size.

Reference: ASME Y14.5-2009, par. 1.3.22

Reference: ISO 10209:2012, Clause 4.6 (from ISO 129-1:2004)

ASME

A taper given to a part so that it can be withdrawn from a model or die.

Reference: ASME Y14.8-2009, par. 1.8.5

ISO

Angle added to a geometrical feature of a pattern or mold to ensure the easy removal of the pattern or molded part from the mold or to improve the quality of the product.

Reference: ISO 8062-1:2007

ASME

ISO

An engineering document or digital data file that discloses (either directly or by reference) by means of graphic or textual presentations, or by combinations of both, the physical or function requirements of an item.

See CAD Drawing

Reference: ASME Y14.100-2004, par. 3

Common

A dimension that is derived from the 3D model and cannot be directly modified.

Reference: None

Common

A dimension that, when modified, causes a change to the CAD geometry.

Reference: None

ISO

For a feature of size, the envelope of perfect form at maximum material condition may not be violated.

Reference: None

ISO

A geometrical feature defining a set of a finite number of points (applies to an integral or to a derived feature).

Reference: ISO 17450-1:2011; Clause 3.3.7

ASME

ISO

A physical portion of a part such as a surface, pin, hole, or slot or its representation on drawings, models, or digital data files.

See Geometrical Feature

Reference: ASME Y14.5-2009, par. 1.3.27

ASME

A rectangle divided into compartments containing the geometric characteristic symbols followed by the tolerance value or description, modifiers, and any applicable datum feature references.

Reference: ASME Y14.5-2009, par. 3.4.1

Common

The boundaries of a feature.

Reference: None

ASME

ISO

One cylindrical or spherical surface, a circular element, or a set of two opposed parallel elements or opposed parallel surfaces, each of which is associated directly with a toleranced dimension.

A geometrical shape defined by a linear or angular dimension which is a size.

Reference: ASME Y14.5-2009, par. 1.3.32.1

Reference: ISO 10209:2012, Clause 4.7 (from ISO 129-1:2004)

ASME

An assembly of two (or more) components that are held together with restrained fasteners, such as screws in tapped holes or studs.

Reference: ASME Y14.5-2009, par. B.4

ASME

The condition of a surface or derived median plane having all elements in one plane.

Reference: ASME Y14.5-2009, par. 5.4.2

ASME

ISO

A geometric tolerance that specifies a tolerance zone defined by two parallel planes within which the surface or derived median plane must lie.

A geometrical tolerance that specifies that the extracted (actual) surface of a feature shall be contained between two parallel planes that are separated by the indicated tolerance value.

Reference: ASME Y14.5-2009, par. 5.4.2

Reference: ISO 1101:2012, Clause 18.2

Common

The shape of a feature.

Reference: None

ASME

ISO

A geometric tolerance that controls the form (such as straightness, flatness, circularity and cylindricity) of a feature.

A geometrical tolerance that controls only form deviations of the feature.

Reference: ASME Y14.5-2009, par. 5.2

Reference: ISO 1101:2012; Clause 15

ASME

The condition of a part free of applied forces.

Reference: ASME Y14.5-2009, par. 1.3.35

ISO

The condition of a part subjected only to the forces of gravity.

Reference: ISO 10579:2010

ASME

ISO

A tolerance, usually located in the notes section of a data set, that applies to multiple features of the part.

A tolerance that applies where an individual tolerance indication is not specified.

Reference: ASME Y14.100-2004, par. 4.26.6

Reference: ISO 2768-1,2:1989

ASME

ISO

The symbolic means of indicating geometric characteristics; used to specify the type of control for a geometric tolerance.

A symbol representing a geometrical characteristic.

Reference: ASME Y14.5-2009, par. 3.3.1

Reference: ISO 1101:2012

Common

A system for defining and communicating engineering tolerances. It uses a symbolic language on engineering drawings and CAD models that explicitly describes nominal geometry and its allowable variation.

Reference: None

ISO

A point, line, surface, volume or a set of these items.

Reference: ISO 17450-1:2011; Clause 3.3

ISO

A symbolic language for communicating workpiece requirements on engineering drawings and CAD models.

Reference: None

ASME

The general term applied to the category of tolerances used to control size, form, profile, orientation, location, and runout.

Reference: ASME Y14.5-2009, par. 1.3.62

ISO

The general term applied to the category of tolerances used to control size, form, profile, orientation, location, and run-out.

Reference: None

ISO

The general term applied to the category of tolerances used to control size, form, profile, orientation, location, and run-out.

Reference: None

ISO

A geometrical feature belonging to the real surface of the workpiece or to a surface of the model.

Reference: ISO 17450-1:2011; Clause 3.3.5

ISO

A system of fits comprising of shafts and holes tolerance by the ISO code system for tolerances on linear sizes.

Reference: ISO 286-1:210, Clause 3.4.1

ISO

The limit defined by a tolerance or combination of tolerances that exists on or inside the material of a feature.

Reference: ASME Y14.5-2009, 1.3.3

ASME

ISO

The condition in which a feature of size contains the least amount of material within the stated limits of size (e.g., maximum hole diameter, minimum shaft diameter).

The state of the considered extracted feature, where the feature of size is at that limit of size where the material of the feature is at its minimum everywhere, e.g. maximum hole diameter and minimum shaft diameter.

Reference: ASME Y14.5-2009, par. 1.3.38

Reference: ISO 2692, Clause 3.6

ISO

A requirement for a feature of size, defining a geometrical feature of the same type and of perfect form, with a given value for the intrinsic characteristic (dimension) equal to LMVS, which limits the non-ideal feature on the inside of the material.

Reference: ISO 2692, Clause 3.13

ISO

The dimension defining the least material condition of a feature.

Reference: ISO 2692, Clause 3.7

ISO

The size generated by the collective effect of the least material size, LMS, of a feature of size and the geometrical tolerance given for the derived feature of the same feature of size.

Reference: ISO 2692, Clause 3.10

ASME

The specified maximum and minimum sizes.

Reference: ASME Y14.5-2009, par. 1.3.55

ASME

A geometric tolerance that controls location of a feature relative to another feature or to a datum reference frame.

Reference: ASME Y14.5-2009, par. 7.1

ASME

A symbol that indicates the material boundary at which a datum feature is to be simulated.

Reference: None

ASME

Refers the size of the feature relative to its limits of size (e.g., RFS, MMC, or LMC).

Reference: None

ASME

ISO

A symbol that indicates the material condition (e.g., RFS, MMC, or LMC) at which the specified tolerance value applies.

See Maximum Material Requirement, MMR, and Least Material Requirement, LMR.

Reference: None

Reference: None

ASME

The limit defined by a tolerance or combination of tolerances that exists on or outside the material of a feature.

Reference: ASME Y14.5-2009, par. 1.3.4

ASME

ISO

The condition in which a feature of size contains the maximum amount of material within the stated limits of size (e.g., minimum hole diameter, maximum shaft diameter).

The state of the considered extracted feature, where the feature of size is at that limit of size where the material of the feature is at its maximum everywhere, e.g. minimum hole diameter and maximum shaft diameter.

Reference: ASME Y14.5-2009, par. 1.3.39

Reference: ISO 2692, Clause 3.4

ISO

A requirement for a feature of size, defining a geometrical feature of the same type and of perfect form, with a given value for the intrinsic characteristic (dimension) equal to MMVS, which limits the non-ideal feature on the inside of the material.

Reference: ISO 2692, Clause 3.12

ISO

The dimension defining the maximum material condition of a feature.

Reference: ISO 2692, Clause 3.5

ISO

The size generated by the collective effect of the maximum material size, MMS, of a feature of size and the geometrical tolerance given for the derived feature of the same feature of size.

Reference: ISO 2692, Clause 3.10

ASME

ISO

A combination of design model, annotation, and attributes that describes a product.

A combination of design model, annotations, and attributes that describes a product.

Reference: ASME Y14.41-2012, par. 3.21

Reference 10209:2012, Clause 9.16.1 (from ISO 16792:2006)

Common

A feature that consists of multiple surfaces.

Reference: None

Common

The stated value of a dimension.

Reference: None

ISO

A modifying symbol that appears near the tolerance frame and indicates that only concave deviations from flat are permissible.

Reference: ISO 1101:2012, Clause 6.3

ASME

ISO

A part that has some flexibility and for which some dimensions and tolerances apply under a specified restraint (as indicated by a note).

A part which deforms to an extent that in the free state is beyond the specified dimensional and/or geometrical tolerances.

Reference: None

Reference: ISO 10579:2010

Common

The sequence in which datum features are referenced in a feature control frame (e.g., primary, secondary, tertiary).

Reference: None

ASME

ISO

A geometric tolerance that controls angular relationships.

A geometrical tolerance that controls orientation and form deviations of the feature.

Reference: ASME Y14.5-2009, par. 6.2

Reference: ISO 1101:2012; Clause 15

ASME

The condition of a surface or a feature’s center plane, equidistant at all points from a datum plane; or a feature’s axis, equidistant along its length from one or more datum planes or datum axes.

Reference: ASME Y14.5-2009, par. 6.3.1

ISO

A geometrical tolerance that specifies that the extracted (actual) surface, line, median line or median plane shall be contained between two parallel planes separated by the indicated tolerance value which are parallel to a datum axis or datum plane.

Reference: ISO 1101:2012, Clause 18.9

Common

A variable in the CAD system.

Reference: None

Common

A dimension that defines the size, orientation, or location of a CAD feature.

Reference: None

ASME

One item, or two or more items joint together, that is not normally subject to disassembly without destruction or impairment of designed use.

Reference: ASME Y14.100-2004, par. 3

ISO

A model in which the product described is a single item.

Reference: ISO 10209:2012 (from ISO 29845:2011)

ASME

ISO

Two or more features or features of size to which a locational geometric tolerance is applied and are grouped by one of the following methods: nX, n COAXIAL HOLES, ALL OVER, A↔B, n SURFACES, simultaneous requirements, or INDICATED.

Two or more features or features of size to which a locational geometric tolerance is applied and are grouped by a notation such as nx.

Reference: ASME Y14.5-2009, par. 1.3.42

Reference: None

ASME

The condition of a surface, a feature’s center plane, or a feature’s axis at a right angle to a datum plane or datum axis.

Reference: ASME Y14.5-2009, par. 6.3.1

ISO

A geometrical tolerance that specifies that the extracted feature shall be contained between two parallel planes separated by the indicated tolerance value which are perpendicular to a datum axis or datum plane.

Reference: ISO 1101:2012, Clause 18.10

ASME

ISO

A geometric tolerance that defines a zone within which the center, axis, or center plane of a feature of size is permitted to vary from a true (theoretically exact) position or, where specified on an MMC or LMC basis, a boundary located at the true position, that may not be violated by the surface or surfaces of the considered feature of size.

A geometrical tolerance that specifies that the extracted center point, median line, median plane, or surface of a feature shall be contained within the specified zone from the theoretically exact location.

Reference: ASME Y14.5-2009, par. 7.2

Reference: ISO 1101:2012, Clause 18.12

Common

The main datum reference frame for the model. It usually orients and locates the model in the assembly.

Reference: None

ASME

The outline of a surface, a shape made up of one or more features, or a two-dimensional element of one or more features.

Reference: ASME Y14.5-2009, par. 8.2

ISO

A geometrical tolerance that specifies that in each section, the extracted profile shall be contained between two equidistant lines enveloping circles of a diameter equal to the indicated tolerance, the centers of which are situated on a line having the theoretically exact geometrical form.

Reference: ISO 1101:2012, Clause 18.5

ISO

A geometrical tolerance that specifies that the extracted surface shall be contained between two equidistant enveloping spheres of a diameter equal to the indicated tolerance, the centers of which are situated on a surface having the theoretically exact geometrical form.

Reference: ISO 1101:2012, Clause 18.7

ASME

A geometric tolerance that defines a two-dimensional tolerance zone at each line element of the feature relative to the true profile.

Reference: ASME Y14.5-2009, par. 8.2.1.2

ASME

A geometric tolerance that defines a three-dimensional tolerance zone extending along the length and width (or circumference) of the feature relative to the true profile.

Reference: ASME Y14.5-2009, par. 8.2.1.1

ASME

ISO

A geometric tolerance used to control form or a combinations of size, form, orientation and location of a feature relative to a true profile.

A geometric tolerance used to control form or a combinations of size, form, orientation and location of a feature relative to a line or a surface having the theoretically exact geometrical form.

Reference: ASME Y14.5-2009, par. 8.2

Reference: None

ASME

ISO

A tolerance zone that is projected above the design model surface.

A tolerance zone placed outside the extent of the toleranced feature.

Reference: ASME Y14.5-2009, par. 7.4.1

Reference: ISO 1101:2012; Clause 13

ISO

An additional requirement for a feature of size used as an addition to the maximum material requirement, MMR, or the least material requirement, LMR, to indicate that the size tolerance is increased by the difference between the geometrical tolerance and the actual geometrical deviation.

Reference: ISO 2692:2006, Clause 3.14

ISO

Indicates that a datum feature simulator progresses from MMB toward LMB until it makes maximum contact with the extremities of a feature.

Reference: ASME Y14.5-2009, par. 1.3.49

ASME

ISO

Indicates that a geometric tolerance applies at any increment of size of the actual mating envelope of the feature of size.

A condition where the size dimension and geometrical tolerances for a feature of size apply independently.

Reference: ASME Y14.5-2009, par. 1.3.48

Reference: None

ASME

ISO

The application of force(s) to a part to simulate its assembly or functional condition resulting in possible distortion of the part from its free-state condition.

A force applied to a workpiece during measurement, which may result in geometrical distortion.

Reference: ASME Y14.5-2009, par. 1.3.50

Reference: ISO 10579:2010

ISO

A geometrical tolerance that specifies that the extracted circumferential line, in any cross-section, shall be contained between two coplanar concentric circles with a difference in radii that is equal to the indicated tolerance value.

Reference: ISO 1101:2012, Clause 18.3

ASME

The form of an individual regular feature of size is controlled by its limits of size.

Reference: ASME Y14.5-2009, par. 2.7.1

ASME

RFS applies, with respect to the individual tolerance, and RMB applies, with respect to the individual datum feature reference, where no modifying symbol is specified.

Reference: ASME Y14.5-2009, par. 2.8

ASME

A tolerance used to control the functional relationship of one or more features to a datum axis established from a datum feature specified at RMB.

Reference: ASME Y14.5-2009, par. 9.2

ASME

A geometric tolerance that is not considered to be part of a simultaneous requirement set.

Reference: ASME Y14.5-2009, par. 4.19

ASME

Where two or more geometric tolerances apply as a single pattern or part requirement. A simultaneous requirement applies to position or profile tolerances that reference identical datum reference frames.

Reference: ASME Y14.5-2009, par. 4.19

ISO

A point, straight line, plane or helix from which the location and orientation of features, or both, can be defined.

Reference: ISO 17450-1:2011; Clause 3.3.1.1.3

ASME

ISO

A dimension between two opposed surfaces, line elements, or points belonging to a feature of size.

A dimension between two opposed surfaces, line elements, or points belonging to a feature of size.

Reference: None

Reference: None

ASME

The assigning of tolerances to related components of an assembly based on sound statistics (such as the assembly tolerance is equal to the square root of the sum of the squares of the individual tolerances).

Reference: ASME Y14.5-2009, par. 2.17

ASME

The condition where an element of a surface, or a derived median line, is a straight line.

Reference: ASME Y14.5-2009, par. 5.4.1

ISO

A geometrical tolerance that specifies that …

Common

A feature that represents a portion of a multi-surface feature.

Reference: None

ASME

The condition where the median points of all opposed or correspondingly located elements of two or more feature surfaces are congruent with a datum axis or center plane.

Reference: ASME Y14.5-2009, par. 7.7.2

ISO

A geometrical tolerance that specifies that the extracted median surface shall be constrained between two parallel planes separated by the indicated tolerance value, which are symmetrically disposed about a datum plane.

Reference: ISO 1101:2012, Clause 18.14

ASME

A symbol that indicates that a geometric tolerance applies only to the tangent plane of the tolerance surface.

Reference: ASME Y14.5-2009, par. 6.5

ISO

Dimensions that indicate the theoretically exact location, orientation, or profile.

Reference: ISO 1101:2012, Clause 11

ASME

ISO

The total amount a specified dimension is permitted to vary. The tolerance is the difference between the maximum and minimum limits.

The total amount a specified dimension is permitted to vary.

Reference: ASME Y14.5-2009, par. 1.3.60

Reference: None

Common

A calculation to determine the effect of the accumulation of tolerances on product requirements.

Reference: None

ISO

A rectangular frame divided into two or more compartments that contain a geometrical characteristic symbol, a tolerance value with optional modifiers, and datum indications, if needed.

Reference: ISO 1101:2012

Common

The area or volume that represents the total amount that a feature is permitted to vary from the specified dimensions.

Reference: None

ASME

ISO

A geometric tolerance that provides control of all surface elements. The tolerance is applied simultaneously to all circular and profile measuring position as the part is rotated about the datum axis.

A geometrical tolerance that specifies that the extracted surface shall be contained between …

Reference: ASME Y14.5-2009, par. 9.4.2

Reference: ISO 1101:2012, Clause 18.16

ASME

A symbol, ▷, following a datum feature reference in the feature control frame indicates that the basic location of the datum feature simulator is unlocked and the datum feature simulator is able to translate within the specified geometric tolerance to fully engage the feature.

Reference: ASME 15.5, par 4.11.10

ASME

A symbol that indicates a unilateral or unequally disposed profile tolerance.

Reference: ASME Y14.5-2009, par. 3.3.22

ISO

A physical (real) part.

Reference: None