Geometric Dimensioning & Tolerancing (GD&T) is an international language that is used on engineering drawings to accurately describe a part.
The GD&T language consists of a well-defined set of symbols, rules, definitions and conventions. It is a precise mathematical language that can be used to describe the size, form, orientation, and location of part features. GD&T is also a design philosophy on how to design and dimension parts.
Geometric Tolerance: The general term applied to the category of tolerance used to control form, profile, orientation, location, and runout.
1. Improve Communication.
2. Provides Better Product Design.
3. Increases Production Tolerance.
4. Reduced scrap.
5. Improved manufacturing tolerances.
6. Clearer part definition.
7. Fewer engineering changes.
8. Improved inspection techniques.
9. Datums are clearly defined.
10. Eliminates the need for many note.
Geometric Characteristic (GD&T) Symbols:
The symbols that are used to specify the type of geometric control.