A feature can be said to be any part of a component that can be dimensioned. All features have a theoretically perfect shape and irregularities from this shape. Datum is used to deal with the irregularities.

Datum feature - for example a surface, edge or cylindrical feature used to establish the location of a datum.

Datum – theoretical exact reference plane, line or axis.

Datum system – more than one datum used to establish the relationship of toleranced features.

 

Understanding the datum system requirements is important to avoid errors in both the manufacturing and measurement process.

1 of 11

Good practice online modules

← Return to the main menu

• Dimensional
• Overview of basic design and interpretation of an engineering drawing
• An introduction to datum
• An introduction to geometric tolerancing
• An introduction to the designer's role when designing a component
• An introduction to the manufacturer's role when designing a component
• An introduction to the inspector's role when designing a component