Features are generally made up from seven geometric shapes (elements) – point, line, plane, circle, cylinder, cone and sphere.

Examples of features could be surfaces, faces, holes, slots, corners, arcs that add up to form an engineering part.

A feature used to establish a datum is referred to as a datum feature.

Datum features:

• are real, important features, used to establish a datum
• may have tolerances specified to them due to the fact variation can occur in the manufacturing process
• can relate various features of the component to each other
• examples are an edge, surface, cylinder feature
• are a locating or positioning feature for a component

2 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