GEOMETRIC TOLERANCES

The charts below give the Symbols forGeometric Tolerancing andAdditional Symbols,

GEOMETRIC TOLERANCES

Geometric dimensioning and tolerancing (GD&T)is a system for defining and communicating engineering tolerances.

It uses a symbolic language on engineering drawings and computer-generated three-dimensional solid models that explicitly describes nominal geometry and its allowable variation.

It tells the manufacturing staff and machines what degree of accuracy and precision is needed on each controlled feature of the part.

GD&T is used to define the nominal (theoretically perfect) geometry of parts and assemblies, to define the allowable variation in form and possible size of individual features, and to define the allowable variation between features.

Geometric dimensioning and tolerancing provides a comprehensive system for symbolically defining the geometrical tolerance zone.

GEOMETRIC TOLERANCE REFERENCE CHART - ASME Y14.5M And ISO/TC 213
TOLERANCECHARACTERISTICSYMBOLDATUM NEEDED APPLICABLE MODIFIERS (RMS, LMC, MMC)
FORMSTRAIGHTNESSStraightnessNOLMC or MMC CAN APPLY TO FEATURE OF SIZE
FORMFLATNESSFlatnessNODOES NOT APPLY
FORM CIRCULARITYCircularityNODOES NOT APPLY
FORMCYLINDRICITYCylindricityNO DOES NOT APPLY
PROFILELINE PROFILELine ProfileNODOES NOT APPLY
PROFILESURFACE PROFILESurface ProfileNODOES NOT APPLY
ORIENTATIONPERPENDICULARITYPerpendicularityYES LMC or MMC CAN APPLY TO FEATURE OF SIZE
ORIENTATIONANGULARITYAngularityYESLMC or MMC CAN APPLY TO FEATURE OF SIZE
ORIENTATIONPARALLELISMParallelismYESLMC or MMC CAN APPLY TO FEATURE OF SIZE
LOCATIONSYMMETRYSymmetryYESRFS ALWAYS
LOCATION POSTIONALPositionalYES AND NO LMC or MMC CAN APPLY TO FEATURE OF SIZE
LOCATIONCONCENTRICITYConcentricityYESRFS ALWAYS
RUNOUT CIRCULAR RUNOUTCircular RunoutYESRFS ALWAYS
RUNOUTTOTAL RUNOUTTotal RunoutYESRFS ALWAYS
ADDITIONAL GEOMETRIC TOLERANCING SYMBOL CHART ASME Y14.5M And ISO/TC 213
DESCRIPTIONSYMBOLSREFERENCES
MAXIMUM MATERIAL CONDITION (MMC)MMCISO 2692/ASME
LEAST MATERIAL CONDITION (LMC)LMCISO 2692/ASME
REGARDLESS OF SIZE FEATURE (RFS)RFSISO/ASME
SPHERICAL DIAMETER (SD)SDISO/AMSE
RADIUSRadiusISO/ASME
DIAMETER DiameterISO/ASME
ENVELOPE REQUIREMENTEnvelopeISO/ASME
FREE STATE CONDITION (NON RIGID PARTS)Free StateISO 10579/ASME
MINOR DIAMETERMinor DiameterISO/ASME
MAJOR DIAMETERMajor DiameterISO/ASME
PITCH DIAMETERPitch DiameterISO/ASME
COMMON ZONECommon ZoneISO/ASME
EXACT DIMENSIONExact PositionISO/ASME
DIMENSION ORIGINDimension OriginISO/ASME
ALL ROUND (PROFILE)All RoundISO NONE/ASME
DATUM FEATURE INDICATIONDatum FeatureISO/ASME
DATUM TARGET INDICATIONDatum Target ISO 5459
PROJECTED TOLERANCE ZONEProjected ZoneISO 10578/ASME