# Geometric tolerancing reference chart

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```					         GEOMETRIC DIMENSIONING
FACTS TO REMEMBER                                            SYMBOLS, RULES, AND GUIDELINES                                                                                                        FACTS TO REMEMBER
FUNC     TOLER
M    – MMC – MAXIMUM MATERIAL CONDITION:             TYPE                SYMBOL           AS SHOWN                            TOLERANCE              MMC LMC       DATUM                           FEATURE CONTROL FRAME:
GAGE      ZONE
THAT CONDITION WHERE A FEATURE OF                                                   ON DRAWING                             ZONE                  OR RFS        USED                                   .005 M        A B C
USED     TYPE
SIZE CONTAINS THE MAXIMUM AMOUNT OF
MATERIAL WITHIN THE STATED LIMITS                                                             .500         .005               TWO PARALLEL            M OR    L
OF SIZE. EXAMPLE: MINIMUM HOLE SIZE                                                                                                                                              YES                                                  TERTIARY DATUM
.004                     LINES .004               CAN                                  A
AND MAXIMUM SHAFT SIZE.                                                                                                                                                           IF                                                  (ONE POINT MIN)
APART                   APPLY          NO           M         H
TO A                                                                       SECONDARY DATUM
STRAIGHTNESS                                                                                            IS            J
L   – LMC – LEAST MATERIAL CONDITION:                                                                                                               FEATURE                                                                     (TWO POINTS MIN)
STATED
THAT CONDITION WHERE A FEATURE OF                                                                                                               OF SIZE.                                                                 PRIMARY DATUM
SIZE CONTAINS THE LEAST AMOUNT OF                                                                                                                                                                                             (THREE POINTS MIN)
MATERIAL WITHIN THE STATED LIMITS                                                             .500         .005               TWO PARALLEL
MODIFIER FOR THE
OF SIZE. EXAMPLE: MAXIMUM HOLE SIZE                                                                  .004                     PLANES, .004
DOES                                                            STATED TOLERANCE
AND MINIMUM SHAFT SIZE.                                                                                                       APART
NOT        NO          NO         D                      STATED TOLERANCE
FLATNESS                                                                         APPLY
RFS – REGARDLESS OF FEATURE SIZE:                                                                                                                                                                              DIAMETER SYMBOL (CYLINDRICAL

FORM
THIS IS THE DEFAULT CONDITION FOR ALL                                                                                                                                                                          TOLERANCE ZONE)
GEOMETRIC TOLERANCES. NO BONUS                                                                                                                                                                           GEOMETRIC CHARACTERISTIC SYMBOL
TOLERANCES ARE ALLOWED. FUNCTIONAL                                                            .500         .005               TWO CONCEN–
GAGES MAY NOT BE USED.                                                                                                        TRIC CIRCLES
.004                      .004 APART                DOES
BASIC SENTENCE STRUCTURE: WHEN
NOT        NO          NO         B
USING THE ENGLISH LANGUAGE TO SAY
P   – PROJECTED TOLERANCE ZONE: WHEN                                                                                                                     APPLY
CIRCULARITY                                                                                                                 WHAT IS IN THE FEATURE CONTROL FRAME.
THE SYMBOL IS SHOWN, IT MEANS THE
YOU MAY USE THE FOLLOWING CONNECTING
STATED TOLERANCE ZONE IS EXTENDED
WORDS:
BEYOND THE SURFACE OF THE PART, NOT                                                                                           TWO CONCEN–
WITHIN THE PART.                                                                              .500         .005
TRIC CYLINDERS                                                                            .005 M       A B C
.004                     .004 APART                 DOES
ST – STATISTICAL TOLERANCE: A                                                                                                                            NOT        NO          NO         E                      WITHIN             RELATIVE TO
TOLERANCE FOR A PART OF AN                                                                                                                           APPLY
CYLINDRICITY
ASSEMBLY BASED ON THE RESULTS FROM                                                                                                                                                                       EXAMPLE: THE POSITION OF THE
A STATISTICAL CALCULATION. THE DESIRED                                                                                                                                                                   FEATURE AXIS MUST BE WITHIN A .005
RESULT IS LARGER TOLERANCES.                                                                                                                                                                             TOLERANCE ZONE AT MMC RELATIVE TO
TWO PARALLEL           M OR     L                             A
.004 A                                                                       YES                     DATUM FEATURES A, B, AND C.
PLANES.004               CAN                                  D
F   – FREE STATE: THIS SYMBOL INDICATES                                                                                                                                           IF
APART                   APPLY
THE PARTS MUST NOT BE RESTRICTED                                                                                                                                 YES          M         G        BONUS TOLERANCE: WHEN MMC IS
A                                     TO A
DURING INSPECTION.                                                                                                                           A                                IS            H      SHOWN MODIFYING A PARTICULAR
PARALLELISM                                                                    FEATURE
STATED                 TOLERANCE, THE STATED TOLERANCE
OF SIZE.                               J
APPLIES ONLY WHEN THE FEATURE BEING
A – DATUM SYMBOL: THIS SYMBOL IS
ORIENTATION

ATTACHED TO A PLANE OR SIZE                                                                                                 TWO PARAL–                                                  A      CONTROLLED IS AT MMC. THE BONUS IS
.004 A                                                M OR    L
FEATURE THAT MUST BE CONTACTED                                                                                              LEL PLANES                                       YES               THE DIFFERENCE BETWEEN THE ACTUAL SIZE
CAN                        IF        D      AND THE MMC SIZE AND MAY BE ADDED
FOR MACHINING AND INSPECTION.                                                                                                   .004 APART
APPLY          YES          M         G      DIRECTLY TO THE ORIGINAL TOLERANCE.
A          TO A
PERPEN–                             A                                                                     IS
– BASIC DIMENSION: THESE                                                                                                                FEATURE                                H      EXAMPLE:
DICULARITY                                                                                               STATED
DIMENSIONS HAVE NO TOLERANCE.                                                                                          90˚                  OF SIZE.                               J                                        ACTUAL     .503
.500    .507
THEY ONLY LOCATE A TOLERANCE ZONE.                                                                                                                                                                                                     MMC      .500
TWO PARALLEL          M OR     L                             A                  .005 M    A
.004 A                                                                       YES                                                 BONUS      .003
PLANES .004
– DIAMETER SYMBOL: THIS SYMBOL                                                                                                                     CAN                        IF        D
APART
REPLACES THE WORD "DIAMETER." IT                                                                 15˚                                              APPLY          YES          M         G      AT MMC THE HOLE MUST BE POSITIONED
15˚              TO A
SHOULD BE USED ANYWHERE THERE IS A                                                                              A                          A                                      IS               WITHIN A CYLINDRICAL TOLERANCE ZONE OF
ANGULARITY                                                                    FEATURE                                H
DIAMETER ON THE DRAWING, AND WHEN                                                                                                                                               STATED             .005 DIAMETER. AS THE EXAMPLE SHOWS,
A TOLERANCE ZONE IS CYLINDRICAL.                                                                                                                     OF SIZE.                               J      THE HOLE HAS DEPARTED FROM MMC BY
.003. THE .003 BONUS TOLERANCE MAY
.004                      TWO LINES                                                          NOW BE ADDED TO THE ORIGINAL .005
TOLERANCE ZONES: ALL TOLERANCE
.004 APART                        MAY BE                           ZONE FOR A TOTAL OF .008 TOLERANCE.
ZONES SHOWN IN THE FEATURE CONTROL                                                                                                                       DOES
ALONG TRUE                         USED
FRAME ARE TOTAL. EXAMPLE: FLATNESS                                                                                                                        NOT                    NO         C
PROFILE                          OR
WITHIN .004 MEANS THAT TWO PARALLEL                                      PROFILE                                                                         APPLY                                       FUNCTIONAL GAGES: DEVICES THAT
MAY NOT
PROFILE

PLANES NO MORE THAN .004 APART                                          OF A LINE                                                                                                                  MEASURE THE COLLECTIVE EFFECTS OF SIZE
DEFINE THE TOLERANCE ZONE.                                                                                                                                                                         AND GEOMETRIC TOLERANCES AT THE SAME
TIME. IT REPRESENTS A SIMULATED
.004 A                    TWO PLANES                                                           MATING CONDITION.
– DATUM TARGETS: USED TO LOCATE                                                                                 .004 APART                          MAY BE                    D
SPECIFIC POINTS, LINES, OR AREAS                                                                                                           DOES
A1                                                                                                                           ALONG TRUE                           USED
ON PARTS USED FOR SUPPORT FOR                              PROFILE                                                                          NOT                    NO         E        BONUS TOLERANCES AND FUNCTIONAL
PROFILE                            OR
MACHINING AND INSPECTION COMMONLY                                         OF A                               A                           A               APPLY                              F      GAGES: DIRECTLY APPLICABLE TO ANY
MAY NOT
USED ON RIGID PARTS LIKE CASTINGS AND                                    SURFACE                                                                                                                   GEOMETRIC CHARACTERISTIC THAT IS
FORGINGS AND NON-RIGID PARTS MADE                                                                                                                                                                  MODIFIED BY M .
FROM PLASTIC, RUBBER, OR SHEET METAL.
.004 A                        CONCENTRIC
A           CIRCLES                                                              SHIFT: AS A DATUM FEATURE OF SIZE,
A
DATUM REFERENCE FRAME: (THREE PLANE                                                                                         .004 APART               RFS                                         THAT IS GEOMETRICALLY CONTROLLED,
CONCEPT). THE CONCEPT OF USING                                                                                                                                       YES         NO         B      DEPARTS FROM MMC, ADDITIONAL
CIRCULAR                                                                     ALWAYS
MUTUALLY PERPENDICULAR FEATURES OF A                                                                                                                                                               TOLERANCE MAY BE CONSIDERED FOR THE
RUNOUT

PART TO CONTROL ITS FREE MOVEMENT IN                                     RUNOUT                                                                                                                    CONTROLLED FEATURES. THIS ADDITIONAL
SPACE (DEGREES OF FREEDOM). SEE DATUM                                                                                                                                                              TOLERANCE DOES NOT ADD DIRECTLY TO
SYMBOL AND DATUM TARGETS.                                                                                                   TWO CONCENTRIC                                                         THE ORIGINAL TOLERANCE BUT MUST BE
.004 A                                                                                              APPLIED TO THE PATTERN OF FEATURES AS A
A        CYLINDERS  A
.004 APART                                                            GROUP. IT IS CONSIDERED A TOLERANCE
RFS
YES         NO         E      THAT ALLOWS THE CONTROLLED FEATURES
ALWAYS
TOTAL                                                                                                                    TO SHIFT AS A GROUP.
RUNOUT
VIRTUAL CONDITION: THE COLLECTIVE
.250     .004                                                                                         EFFECT OF SIZE AND GEOMETRIC
.022 ZONE                                                           TOLERANCES THAT MUST BE CONSIDERED
.014 M A B C                     AT LMC                                                              IN DETERMINING THE FIT OR CLEARANCE
M OR    L                                    BETWEEN MATING PARTS OR FEATURES.
FREE MOVEMENT                                                                                               B                     .014 ZONE                                      YES
CAN                                  G
RESTRICTED MOVEMENT                                                                                     AT MMC                                          IF                   TO CALCULATE VIRTUAL CONDITION:
.380                                       APPLY
YES          M         H
TO A                                                EXTERNAL FEATURES:
LIMITS OF SIZE RULE: WHERE ONLY A                                                                                                                                           IS
POSITION                                                            .620    FEATURE                                J          MMC SIZE + TOLERANCE OF FORM,
SIZE DIMENSION IS GIVEN. a) THE SIZE                                                                                                                                        STATED
OF SIZE.                                          ORIENTATION, OR LOCATION
DIMENSIONS AT ANY CROSS SECTION MUST
BE WITHIN THE SIZE TOLERANCE. b) THE
A             .620 C                         .380                                                                INTERNAL FEATURES:
SURFACE(S) SHALL NOT EXTEND BEYOND                                                                                             TRUE CENTER                                                             MMC SIZE – TOLERANCE OF FORM,
THE PERFECT FORM DEFINED BY THE MMC                                                                                                                                                                    ORIENTATION, OR LOCATION
SIZE. c) THE FORM MAY VARY WITHIN AN
.004 AROUND                                                        A VIRTUAL CONDITION WILL EXIST ONLY FOR
LOCATION

ENVELOPE BETWEEN THE MMC AND LMC.                                                                   .004 A                      DATUM AXIS                                                         TOLERANCES THAT CONTROL SIZE FEATURES.
A
GEOMETRIC TOLERANCE RULE: GEOMETRIC                                                                                                                  RFS
TOLERANCES ARE UNDERSTOOD TO BE                                                                                                                                      YES         NO         J      * THIS COLUMN INDICATES POSSIBLE
ALWAYS
CONCEN–                                                                                                                    TOLERANCE ZONES THAT MAY BE USED WITH
APPLIED RFS. IF MMC OR LMC IS
REQUIRED, IT MUST BE PLACED IN THE                                       TRICITY                                                                                                                   THE VARIOUS CONTROLS. THE DIFFERENT
FEATURE CONTROL FRAME. SEE MMC, LMC,                                                                                                             A                                                 TOLERANCE ZONES ARE SHOWN ALONG THE
OR RFS COLUMN.                                                                                                                                                                                     BOTTOM OF THIS CHART.

A                            A
PITCH DIAMETER RULE: TOLERANCES                                                                                                                                                                           THIS CHART IS PROVIDED FOR
THAT APPLY TO SCREW THREADS APPLY TO                                                                                                                                                                      INFORMATIONAL PURPOSES ONLY.
THE AXIS OF THE THREAD DERIVED FROM                                                                                                                                                                       THE INFORMATION IS BASED UPON
THE PITCH CYLINDER. IF ANOTHER PART OF                                                                                                                 RFS                                  G                    ASME Y14.5M - 1994.
THREAD IS TO BE USED TO DERIVE THE                                                                                                                                   YES         NO
ALWAYS                                 H
AXIS, IT MUST BE STATED BENEATH THE                                     SYMMETRY                                                                                                                                             GENIUM PUBLISHING CORP.
FEATURE CONTROL FRAME. ANY OTHER                                                                                             .004 EQUALLY                                                                                    ONE GENIUM PLAZA
FEATURE THAT HAS A PITCH DIAMETER MUST                                                          .004 A                                                                                                                       SCHENECTADY, NY 12304
DISPOSED FROM
HAVE THE DATUM FEATURE STATED.                                                                                               CENTER PLANE                                                                                    (518) 377-8854

A   PARALLEL LINES         B   PARALLEL LINES    C             PARALLEL LINES   D   PARALLEL PLANES                E    PARALLEL PLANES         F    PARALLEL PLANES   G    PARALLEL PLANES   H   PARALLEL PLANES           J    CYLINDER ZONE

```
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