Geometric Dimensioning and Tolerances: Symbols (ASTM Y14.5-2009)
![GDT-angularity](https://i1.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-angularity.gif?resize=75%2C75) |
Angularity – The condition of a surface, centerplane or axis being exactly at a specified angle |
![GDT-circularity](https://i1.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-circularity.gif?resize=75%2C75) |
Circularity – A condition where all points of a surface of revolution, at any section perpendicular to a common axis, are equidistant from that axis. |
![GDT-concentricity](https://i0.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-concentricity.gif?resize=75%2C75) |
Concentricity – The condition where the median points of all diametrically opposed elements of a cylinder (or a surface of revolution) are congruent with the axis of a datum feature. |
![GDT-cylindricity](https://i1.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-cylindricity.gif?resize=75%2C75) |
Cylindricity – A condition of a surface of revolution in which all points of the surface are equidistant from a common axis. |
![GDT-flatness](https://i0.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-flatness.gif?resize=75%2C75) |
Flatness – The condition of a surface having all of its elements in one plane.
|
![GDT-parallel](https://i1.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-parallel.gif?resize=75%2C75) |
Parallelism – The condition that results when a surface, axis or centerplane is exactly parallel to a datum. |
![GDT-perpendicularity](https://i2.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-perpendicularity.gif?resize=75%2C75) |
Perpendicularity – The condition that results when a surface, axis, or centerplane is exactly 90° to a datum. |
![GDT-position](https://i0.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-position.gif?resize=75%2C75) |
Position – The zone within which the axis or center plane of a feature is permitted to vary from true (theoretically exact) position. |
![GDT-profline](https://i0.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-profline.gif?resize=75%2C75) |
Profile of a Line Control – A geometric tolerance that limits the amount of error for line elements relative to their true profile. |
![GDT-profsurf](https://i0.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-profsurf.gif?resize=75%2C75) |
Profile of a Surface Control – A geometric tolerance that limits the amount of error a surface can have relative to its true profile. |
![GDT-runout](https://i0.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-runout.gif?resize=75%2C75) |
Circular Runout – A composite control that affects the form, orientation, and location of circular elements of a part feature relative to a datum axis. |
![GDT-straightness](https://i2.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-straightness.gif?resize=75%2C75) |
Straightness (Axis or Centerplane) – The condition where an axis is a straight line (or, in the case of a centerplane, each line element is a straight line). |
![GDT-symmetry](https://i1.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-symmetry.gif?resize=75%2C75) |
Symmetry – The condition where the median points of all opposed elements of two or more feature surfaces are congruent with the axis or centerplane of a datum feature. |
![GDT-totalrunout](https://i2.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-totalrunout.gif?resize=75%2C75) |
Total Runout – A composite control affecting the form, orientation, and location of all surface elements of a diameter (or surface) relative to a datum axis. |
Geometric Dimensionsing and Tolerances: Modifiers (ASTM Y14.5-2009)
![GDT-allaround](https://i1.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-allaround.gif?resize=75%2C75) |
All-Around Symbol – A circle placed on the bend of the leader line of a profile control. |
![GDT-basicdim](https://i2.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-basicdim.gif?resize=75%2C75) |
Basic Dimension – A numerical value used to describe the theoretically exact size, true profile, orientation, or location of a feature or datum target. |
![GDT-between](https://i1.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-between.gif?resize=75%2C75) |
Between Symbol – A double ended arrow that indicates the tolerance zone extends to include multiple surfaces. |
![GDT-controlledradius](https://i2.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-controlledradius.gif?resize=75%2C75) |
Controlled Radius – A radius with no flats or reversals allowed. The symbol for a controlled radius is “CR.” |
![GDT-datumfeature](https://i2.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-datumfeature.gif?resize=75%2C75) |
Datum Feature – A part feature that contacts a datum. |
![GDT-datumtarget](https://i0.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-datumtarget.gif?resize=135%2C75) |
Datum Target – A symbol that describes the shape, size, and location of gage elements that are used to establish datum planes or axes. |
![GDT-FCF](https://i0.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-FCF.gif?resize=215%2C75) |
Feature Control Frame – A rectangular box that is divided into compartments within which the geometric characteristic symbol, tolerance value, modifiers, and datum references are placed. |
![GDT-lmc](https://i0.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-lmc.gif?resize=75%2C75) |
Least Material Condition – The condition in which a feature of size contains the least amount of material everywhere within the stated limits of size. |
![GDT-mmc](https://i1.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-mmc.gif?resize=75%2C75) |
Maximum Material Condition – The condition in which a feature of size contains the maximum amount of material everywhere within the stated limits of size. |
![GDT-projected](https://i2.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-projected.gif?resize=75%2C75) |
Projected Tolerance Zone – A tolerance zone that is projected above the part surface. |
![GDT-radius](https://i2.wp.com/www.dfwmachine.com/wp-content/uploads/2011/06/GDT-radius.gif?resize=75%2C75) |
Radius – A straight line extending from the center of an arc or circle to its surface. |
Reference Specification for Geometric Dimensioning and Tolerances:
ASTM Y14.5-2009