What is a surface profile tolerance?

What is a surface profile tolerance?

Description: Profile of a surface describes a 3-Dimensional tolerance zone around a surface, usually which is an advanced curve or shape. Usually, when surface profile is required, there are no tolerances on the dimensions that describe the surface and use the GD callout to give the acceptable range.

What is surface profile in GD?

The profile of a surface specification defines a 3-dimensional tolerance zone equidistant from the theoretically exact shape or curve (i.e. the “True Profile”) to control all the points along the surface to be within a tolerance range.

Which of the following symbol of geometrical tolerance applies to surface?


Type of control Geometric characteristics Unicode character
Profile Profile of a surface ⌓ U+2313
Orientation Perpendicularity ⟂ U+27C2
Orientation Angularity ∠ U+2220

How do you read Unilateral tolerance in GD?

Unilateral tolerance is a type of unequally disposed tolerance where variation from the true profile is only permitted in one direction. GD notation for this is identical to unequally disposed tolerance, with the number trailing the “U” symbol either zero or equal to the tolerance amount.

How do I find my surface profile?

When pressed against a roughened steel surface, the foam collapses and forms an impression of the surface. Placing the compressed tape between the anvils of a micrometric thickness gage and subtracting the contribution of the incompressible substrate, 2 mils, gives a measure of the surface profile.

What are GD symbols?

Geometric Dimensioning and Tolerancing (GD) is a language of symbols and standards designed and used by engineers and manufacturers to describe a product and facilitate communication between entities working together to produce something.

How many symbols are there in GD?

Geometric tolerances are specified using symbols on a drawing. Currently, we have 16 symbols for geometric tolerances, which are categorized according to the tolerance they specify.