dimensioning and tolerancing training
tutorial in Geometric Tolerancing GDT
To provide basic skills to specify or interpret geometric tolerances.
the international engineering language of Geometric Dimensioning
& Tolerancing (GDT), gd t symbols is essential for communicating
in today's highly competitive global marketplace. This tutorial
builds the ability to read and interpret GDT symbols, which provide
detail information about the function and relationship of part features
such as, dimensioning, tolerance, runout, datum, profile etc.
I : Introduction to
Dimensioning and tolerancing GDT
is a numerical value expressed in an appropriate unit of measure.
It is indicated on a drawing along with line, arrow, symbols and
notes to define the size and specification of an object.
(Fig. 1 )
is used only for information purposes. The definition REF shall
be indicated immediately under or beside the dimension.
Normally it is either a duplication of a dimension or it is the
accumulated value of other dimensions.
is the allowable variation of a dimension. It is the difference
between the maximum and minimum limits. All dimensions except basic,
reference, nominal, maximum or minimum shall have a tolerance.
See Fig. 1.
Part II . Maximum & Minimum metal condition
training and GDT tutorial