2.7 Accuracy in Design & Manufacture

What does accuracy mean in design and manufacture?

Accuracy refers to the degree of closeness between a measured value and the true or intended value — essential for fit, function, and safety.

What is a tolerance in manufacturing?

Tolerance is the permissible limit of variation in a physical dimension — it defines how much larger or smaller a part can be and still function correctly.

What is measurement and why is it important?

Measurement involves determining length, width, depth, angle, or diameter using tools like calipers, rulers, micrometers — critical for quality control.

Define the term dimension in product design.

A dimension is a numerical value that defines the size or geometry of a product or part, such as length, width, height, or diameter.

What is a datum and how is it used?

A datum is a reference point or surface from which all measurements and marking out are taken to ensure consistency and precision.

What is a jig?

A jig is a custom-made tool that guides cutting or drilling tools to ensure precision and repeatability during manufacturing.

What is a fixture in manufacturing?

A fixture is a device used to hold a workpiece securely in place during machining or assembly to maintain accuracy and safety.

What is a template, and how is it used in design?

A template is a pre-shaped pattern used to trace or cut out identical shapes, especially useful in batch production for consistency.

Why is accuracy important in batch and mass production?

To ensure that interchangeable parts fit correctly, reduce waste, meet quality standards, and improve efficiency in automated processes.