1. Dimensioning and Tolerancing
Chapter 10 continued
Dimensioning and Tolerancing

2. General Notes Relate to the entire part or drawing as a whole
Located next to the title block
Notes:
Material specs
Units
General tolerances
Finish specs
Etc.

3. Delta Notes Refer to a specific area of the part
Note is numbered (usually located with general notes by title block)

4. Local Notes Applied to a specific area of the part by a leader
All text on drawings to be capitol letters

5. Dimensioning Systems
The manner of which dimensions are applied to drawings for different applications.
Selected based on:
How the part will be manufactured
What features of the part are important based on its function
How many features are on the part
The general shape of the part
Systems can be combined to better dimension relationships of features

6. Unidirectional Dimensioning
all text is horizontal and read from the bottom of the sheet.

7. Aligned Dimensioning all text is aligned with the dimension lines
Horizontal dimensions are read from the bottom
Vertical dimensions are read from the right side

8. Rectangular Coordinate Dimensioning (10.61)
Dimensioning linear dimensions to locate features from planes, centerlines and center planes

9. Arrowless Dimensioning (fig 10.14)
Also called Ordinate and Rectangular Coordinate without Dimension Lines
Dimensions shown as extension lines only
Horizontal and vertical dimensions measured from common locations (origin labeled as 0.00)
Size dimensions for holes given in a table

11. Tabular Dimensioning (fig 10.15)
Size and locations given as x, y, z coordinates
Dimensions shown in a table
Features to be shown in table are labeled with letters

13. Chart Drawing (fig 10.16) Multiple parts dimensioned on one drawing
Dims common to all parts are placed on the drawing, dims that differ are placed in a table
Used for parts that have the same shape but different dimensions
Differences between parts can be dimensional or something as minor as a color difference
Cuts down on the number of drawings
Also used in catalogs for ordering parts

15. Chain Dimensioning (fig 10.24)
Also called point to point
Dimensions from one feature to the next
Causes tolerance buildup

16. Datum Dimensioning (not in book)
Each dimension is measured from a common edge
Very commonly used on engineering drawings
Commonly combined with chain dimensioning

17. Polar Coordinate Dimensioning (10.62)
Use of angular dimensions to locate feature
Typically on round parts

18. Dimensioning Symmetrical Objects
Part must be completely symmetrical about a centerline
Can show entire view or partial view
Must show symmetry symbol on centerline

19. Dimensioning Features Angular Surfaces
Can be dimensioned by:
Dims at both end of the angled surface
Dim at one end and angular dim
Flat taper note

20. Chamfers
Chamfer-a slight surface angle to relieve sharp corners or create lead in on a part that will be inserted into a hole.
45 ˚ chamfers can be dimensioned with a note
3X45˚ or 3X3
All other angles require normal dimensioning

22. Conical Taper Dimensioning a cylindrical object that changes diameter
Dimensioned in a view where it appears as a triangle