GD&T SYMBOLS

Dimensioning symbols replace text and are used to minimize language barriers. Many companies produce parts all over the world. A print made in the U.S.A. may be read in several different countries. The goal of using dimensioning symbols it to eliminate the need for language translation.

GD&T uses internationally accepted symbols that for the most part cross all language barriers. This enables the correct interpretation of drawing specifications without language translation. The following tables show the symbols that are used in GD&T. The symbols will be illustrated and explained as the learning material unfolds.

DIMENSIONING SYMBOLS

Term Symbol
Diameter n
Spherical Diameter Sn
Radius R
Spherical Radius SR
Reference Dimension (8)
Counterbore / Spotface v
Countersink w
Number of Places 4X
Depth / Deep x
Dimension not to scale 10
Square (shape) o
Arc Length Arc length symbol
Conical Taper y
Slope z
Symmetry i

GD&T GEOMETRIC CHARACTERISTIC SYMBOLS

Tolerance Type Characteristic Symbol
For individual features Form Straightness u
Flatness c
Circularity e
Cylindricity g
For individual or related features Profile Profile of a Line k
Profile of a Surface d
For related features Orientation Angularity a
Perpendicularity b
Parallelism f
Location Position j
Concentricity r
Symmetry i
Runout Circular Runout h
Total Runout t

GD&T MATERIAL CONDITIONS

Term Symbol
Maximum Material Condition m
Least Material Condition l
Regardless of Feature Size None

ADDITIONAL GD&T SYMBOLS

Term Symbol
Basic Dimension Basic dimension symbol
Between Between symbol
Dimension Origin Dimension Origin symbol
All Around All around symbol
Controlled Radius CR
Statistical Tolerance Statistical Tolerance symbol
Projected Tolerance Zone p
Regardless of feature size s or None
Tangent Plane Datum Feature Symbol
Free State Datum Feature Symbol
Datum Feature Datum Feature Symbol
Datum Target Datum Target Symbol
Target Point Target Point Symbol