Tolerance Types
The tolerancing methods presented are:
- Limit dimensions
- Plus or minus tolerances
- Page or block tolerances
Limit dimensions
Limits are the maximum and minimum size that a part can obtain and still pass inspection. For example, the diameter of a shaft might be specified as follows.
The high limit is placed above the low limit. When both limits are placed on one line, the low limit precedes the high limit.
Plus or minus tolerances
Plus or minus tolerances give a basic size and the variation that can occur around that basic size.
Page or block tolerances
A page tolerance is actually a general note that applies to all dimensions not covered by some other tolerancing type. Block tolerances are placed in the tolerance block to the left of the title block and above the projection block.
