Industrial Member Technical Roughness Guide
TWI Industrial Member Report 1213-2026
By Alan Taylor and Sara Naderizadeh
The precise and accurate determination of the roughness of a component is a critical element of the engineering process, influencing key functional characteristics such as friction coefficient, wear behaviour, and sealing effectiveness. Even minor deviations can lead to premature failure or reduced efficiency. Surface roughness can impact dimensional tolerance and the fit of mating surfaces and surface-related metrics are widely used to ensure process control and the quality assurance for a variety of parts across all industry sectors. Surface roughness also influences the strength of joints in parts, particularly if the joint has been created using adhesive or diffusion bonding technologies. Functional and protective coatings are also sensitive to the roughness of a component.
This Technical Guide has been created to provide Industrial Members with an exclusive overview of the main elements of surface roughness. As a top-level overview to the topic, the guide includes details of the fundamental concepts of surface roughness, key terms and descriptors, geometrical parameters, measurement techniques, standards, applicability, future trends, and more.