Please enable JavaScript.
Coggle requires JavaScript to display documents.
L06-dimentions,tolerances,assembiles - Coggle Diagram
L06-dimentions,tolerances,assembiles
-
Tolerances
The Importance of Tolerance
In practice, parts cannot be manufactured exactly to the dimensions stated in the drawing, due to manufacturing variations. Tolerances are included with dimensions in engineering drawings to take into account these manufacturing limitations.
Types of Tolerance
Bilateral Tolerance: allowed to vary in two directions from the specified dimension. Both directions need not vary by the same amount.
-
-
-
Tolerance is defined as the difference between the upper limit of a dimension and the lower limit of the dimension. Its formula is given by:
-
-
Dimensions in Drawings
How to Dimension
Dimension Text
This is the base dimension. Usually the units (in mm) is not indicated on every dimension text, but at the bottom corner of the drawing.
-
-
Extension Line
Extension lines continue or extend from the surface of the object and establish the size of the dimension. They do not touch the object lines and extend slightly past the dimension line.
Extension Line Offset
A gap between the object surface and the extension line, so it is not confused with the visible lines of the model
Rules of Dimensioning
Dimensions should not be duplicated, i.e. same dimension should not be repeated on different views, or the same information need not be given in two different ways
-
Dimension lines, extension lines and object outlines should not cross or overlap