What is difference between feature and feature of size?
A feature is defined as being a physical portion of a part such as a surface, hole, boss or slot. A feature of size is defined in the 2009 Y14.
What is a feature without size?
Definition: Regardless of Feature Size (RFS) is the default condition of all geometric tolerances by rule #2 of GD and requires no callout. Regardless of feature size simply means that whatever GD callout you make, is controlled independently of the size dimension of the part.
What is a datum feature of size?
A datum feature is the tangible surface or feature of size (comprised of multiple surfaces or revolved surfaces) that is indicated by the datum feature symbol. You can think of them as anchors for the entire part. They are the surface or feature where the other features are referenced from.
Which of the following is considered a feature of size?
A feature of size (FOS) is a cylindrical or spherical surface, drilled hole, or set of two opposed elements or parallel surfaces associated with a size dimension.
What is features in GD & T?
GD is a feature-based system, and parts are composed of features. Geometric tolerances are applied to features by feature control frames. The most frequently used tolerance categories are form, orientation, and location; therefore, the ten associated symbols are the most utilized of the fourteen total GD symbols.
Is a fillet a feature of size?
What is non feature of size Dimension? In an engineering drawing, the dimensions other than the feature of size are called non feature of size dimensions. In the above figure, we have two non feature of size dimensions (the fillet and the chamfer).
Can a feature of size be basic?
Features of size are unique because they: Contain opposed points. Have a reproducible derived median point, axis or center plane. Have limits (are not basic)
Is a cone a feature of size?
In the new standard, a hex, square, cone, or other similar type of features can used as a feature of size and even as a datum feature as long as they are properly related with profile or other geometric controls.
What is a datum feature?
A datum feature is a part feature (or FOS), that contacts a datum during measurement. A datum is a theoretically exact plane (or axis or center-plane), from which dimensional measurement should be made.
How do you select the datum features?
The ASME Y14. 5 2009 Standard tells us, “A datum feature is selected on the basis of its functional relationship to the tolerance feature and the requirements of the design. To ensure proper assembly, corresponding interfacing features of mating parts should be selected as datum features.
Is a diameter a feature of size?
A Regular Feature Of size is one that has a size associated with it (a diameter or a width or a length or a thickness). The special thing about a Regular Feature Of Size that makes it regular is the fact that it has Opposed Surfaces.
What is internal feature of size?
In GD the term feature-of-size (FOS) refers to any surface, or set of parallel surfaces associated with a size dimension. Specific examples of features of size include: A hole diameter (a cylindrical surface)
What are the features of size?
Features Of Size are divided into Regular Features Of Size and Irregular Features Of Size. First we will discuss Regular Features Of Size. They are by far the most common. A Regular Feature Of size is one that has a size associated with it (a diameter or a width or a length or a thickness).
What is a feature-of-size?
In GD the term feature-of-size (FOS) refers to any surface, or set of parallel surfaces associated with a size dimension. Specific examples of features of size include: The example below shows three views of a plate with two holes. There are two dimensions called out in this drawing: a plate thickness and a hole diameter.
What is a “regular feature”?
First of all we should start with our ASME Y14.5’s definitions. A regular feature of size is said to be “one cylindrical or spherical surface (or circular element,) or two opposed parallel elements (or parallel surfaces,) associated with a directly toleranced dimension.”
What does regardless of feature size mean in GD?
Regardless of feature size simply means that whatever GD callout you make, is controlled independently of the size dimension of the part. What do GD symbols mean?