In GD&T, profile tolerance defines a uniform boundary around a surface within which the elements of the surface must lie . Profile is a complex tolerance that simultaneously controls a feature’s form, size, orientation, and sometimes location. ... The top figure shows the profile tolerance applied to a curved surface.
How is profile tolerance measured?
Profile is usually measured using a CMM due to the complexity of some of the surfaces that are called out. The CMM would compare the 3D scan of the profile to the dimensions called out on the drawing to see if it was in spec.
What is a surface tolerance?
Surface tolerance refers to the degree of cleanliness, receptiveness and effectiveness of a substrate metal to support a coating that is applied to its surface as a corrosion prevention method.
Is profile tolerance bilateral?
Bilateral profile tolerance means variation from the true profile is permitted in equally in both directions . Unequally disposed profile tolerance means that more variation from the true profile is permitted in one direction than the other.
What is meant by geometrical tolerance?
Geometrical Tolerancing is a system that allows tolerances to be applied to features rather than dimensions on engineering drawings and CAD models. It allows different aspects of form, orientation and location to be toleranced independently of each other.
What are the 3 types of tolerances?
These are grouped into form tolerance, orientation tolerance, location tolerance, and run-out tolerance , which can be used to indicate all shapes.
How is profile measured?
Profile is usually measured using a CMM due to the complexity of some of the surfaces that are called out. The CMM would compare the 3D scan of the profile to the dimensions called out on the drawing to see if it was in spec.
What is a runout tolerance?
Run-out tolerance is a geometric tolerance that specifies the run-out fluctuation of a target’s feature when the target (part) is rotated on an axis (specified straight line) . A datum is always necessary to indicate run-out tolerance; as such, it is a geometric tolerance for features related to datums. Circular Run-out.
How is profile of a surface calculated?
Surface profile measurement is the measurement of a line across the surface that can be represented mathematically as a height function with lateral displacement, z(x) . With a stylus or optical scanning instrument, profile measurement is carried out by traversing the stylus across a line on the surface.
What is bilateral tolerance example?
The amount that the size of a machine part is allowed to vary above or below a basic dimension ; for example, 3.650 ± 0.003 centimeters indicates a tolerance of ± 0.003 centimeter.
What is bilateral tolerance * 1 point?
Statement 1: Bilateral tolerances are used in mass production techniques . Statement 2: The basic size should be equal to upper and lower limits. ... If unilateral tolerances are specified in place of bilateral, then basic size should be changed to make it bilateral. Basic size is in half way between lower and upper limits.
How do you read bilateral tolerance?
To read or calculate a bilateral tolerance take the nominal size and subtract the minus tolerance. Then take the nominal size and add the plus tolerance . These two numbers will give you the total range which you are allowed.
What is an example of tolerance?
Tolerance is being patient, understanding and accepting of anything different. An example of tolerance is Muslims, Christians and Athiests being friends .
What are types of tolerance?
- Linear Tolerance. Unilateral Tolerance. Bilateral Tolerance. Limit Dimensions.
- Geometric Tolerance. Form Control. Profile Control. Orientation Control. Location Control. Runout.
What is the use of geometrical tolerance?
Geometrical tolerances are used to convey in a brief and precise manner complete geometrical requirements on engineering drawings . They should always be considered for surfaces which come into contact with other parts, especially when close tolerances are applied to the features concerned.
