1. Basic Dimensioning
Rules of Dimensioning

2. Working Drawing
Definition: A drawing from which a part can be produced.
Must be a complete set of instructions
Consists of:
The views needed to describe the shape
Dimensions needed for manufacture
Notes (materials, etc.)

3. Dimensions are noted using:
Extension lines
Dimension lines
Leader s
Notes
Symbols

4. Types of Dimensions Overall dimensions Detail dimensions
overall length.width and height
Detail dimensions
all other dimensions used to describe an object
The standard units measurement
Metric = millimeters
Imperial = inches
Always specify full size dimensions

5. Place dimensions off between or above views

6. Dimension a feature where the shape is shown

7. Dimension a feature only once and always to an object line

8. Omit one detail dimension in a chain

9. Place consecutive detail dimensions in line

10. 8-2 Dimensioning Circular Features
Diameters and radii
Cylindrical and slotted holes

11. Dimensioning Cylindrical Objects

12. Repetitive features
Dimensioned once with an indication of how many repetitions are required

13. Chamfers
Normally dimensioned using angle and linear length

14. Knurls
Expressed in terms of type, pitch, and diameter before and after knurling

15. Undercuts
Expressed as width by diameter
Plain Undercut

16. Polar Coordinate Dimensioning
Commonly used in circular planes or circular configurations of features.
Indicates the position of a point, line, or surface with a linear dimension and an angle.

17. Chain Dimensioning
A series of dimensions is applied on a point-to-point basis.
Chain dimensioning may allow undesirable tolerance accumulation.

18. Datum or Common-Point Dimensioning
Several dimensions are measured from a common point or line.