Datum targets are specific points used to establish datums. Used when dealing with components such as castings, fixturing, or moulded parts that have rough surfaces and the edges will not be reliable enough to establish datums.

There are three types of datum target:

• datum target area
• datum target points
• datum target lines

Datum target area

Target area can be rectangular or circular and is shown on the drawing by phantom lines. This indicates that the component is to be located for manufacture or inspection by using the areas indicated by the datum target. This can be achieved by using a circular location peg.

Example of a datum target frame

This example shows the location zone for manufacture or measurement to be anywhere within the circular area of a diameter of 8 mm with a theoretical centre being at 15 mm by 15 mm from the corner. A1 is the reference name (datum feature and datum target number).

10 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