How are datums identified on a process drawing?

Datums are critical reference points used in engineering and manufacturing to ensure accuracy and consistency in the dimensional control of parts. On a process drawing, datums are typically identified using letters, which allows for clear communication and differentiation between multiple datums present in a design. Each letter represents a specific reference point or surface, making it easier to refer to them throughout technical documents and manufacturing processes.

This method of identification helps prevent confusion and ensures that everyone involved in the production, quality control, or measurement of parts understands which reference is being discussed. Utilizing letters for datums standardizes their identification, facilitating a common understanding among engineers, machinists, and inspectors.