Full definition
Science studying friction, wear, and lubrication between surfaces in relative motion. Relevant for selecting: lubricants (ISO VG viscosity grade, type: mineral, synthetic, biodegradable), wear part materials (rubber, polyurethane, UHMWPE), surface coatings (nitriding, hard chrome, DLC), and design parameters (contact pressure, sliding speed). Reducing friction = lower energy consumption and longer component life.