Chapter Chapter Chapter
After studying this chapter, you will be able to:
a72 Describe the purpose of proﬁ le geometric tolerances.
a72 Apply or interpret proﬁ le geometric tolerances on drawings.
a72 Draw or interpret proﬁ le of a line tolerances.
a72 Explain methods used to apply bilateral tolerances.
a72 Explain methods used to apply unilateral tolerances.
a72 Apply or interpret proﬁ le of a surface tolerances.
a72 Draw or interpret coplanar proﬁ le tolerances.
a72 Explain the types of controls speciﬁ ed by composite proﬁ le tolerances.
Composite proﬁ le tolerance
Coplanar proﬁ le tolerance
Locating tolerance zone
Non-uniform proﬁ le
Proﬁ le form and orientation tolerance zone
Proﬁ le geometric tolerances
Proﬁ le of a line tolerance
Proﬁ le of a surface tolerance
Proﬁ le tolerance
True proﬁ le
Unequally disposed proﬁ le
Unilateral proﬁ le
This chapter explains the concepts and techniques of dimensioning and
tolerancing to control the profile of geometric shapes. Profile geometric tolerances
control the form, orientation, and/or location of straight lines or surfaces, arcs, and
Profile can be characterized as the outline of an object represented either by
an external view or a cross section through the object. The true profile or actual
desired shape of the object is the basis of the profile tolerance. The true profile is
defined by basic dimensions. The profile tolerance specifies a uniform boundary
along the true profile within which the elements of the surface must lie. Profile can
be used to control form or combinations of size, form, and orientation. When used
as a refinement of size, the profile tolerance must be contained within the size
tolerance. Profile geometric tolerances are always regardless of feature size. Datum
reference can be applied with boundary conditions (RMB, LMB, MMB) if the datum
feature is a feature of size.