GD&T Profile Definition. Profile is a three-dimensional tolerance that applies in all directions regardless of the drawing view where the tolerance is specified. It is usually used on parts with complex outer shape and a constant cross-section like extrusions.What is the difference between GD&T tolerance and profile tolerance?
The profile types of GD&T tolerance are used for controlling a curved (or flat sometimes) surfaces and the edges of the surfaces. Profile tolerances may or may not use datum. If nothing is specified, profile tolerance zone is unilateral against the ideal surface or curve.What is the profile of a surface?
The profile of a surface is the 3D form of the profile of a line GD&T control. By applying profile of a surface control, we ensure that the indicated curved (or flat) surface should lie in between a set of parallel surfaces with specified distance.How to use the profile of a surface with datum references?
You can either use the profile of a surface with datum references or without, depending on the functional requirements for the design. Profile of a surface is a GD&T symbol used with datum if you want to control every aspect of a feature’s geometry like size, shape, orientation, and even location .