DIN 9021, a German standard, outlines the requirements for the surface roughness of machined parts, ensuring consistency and quality in manufacturing processes. This standard provides a framework for evaluating and specifying surface roughness, enabling manufacturers to control and optimize the texture of machined surfaces. By establishing a common language and set of parameters, DIN 9021 facilitates communication between designers, manufacturers, and quality inspectors, ensuring that finished products meet the required specifications and performance expectations.