Full definition
German standard specifying dimensions, tolerances, and testing requirements for narrow-section V-belts with metric profiles: SPZ (10 mm top width), SPA (12.7 mm), SPB (16.3 mm), and SPC (22 mm). These metric profiles were developed as improvements over classical (A, B, C, D, E) profiles, transmitting more power per belt width due to optimized cross-section geometry. DIN 7753 complements ISO 4184 (which covers both classic and metric profiles) and is the primary reference for V-belt specifications in Europe and Latin America. Key specifications: belt cross-section dimensions and tolerances, datum length (Ld) measurement method, tensile strength, elongation at rated tension, and dynamic fatigue test requirements. DIN 7753 Part 1 covers endless V-belts, Part 2 covers matched sets. The narrow metric profiles (SPZ/SPA/SPB/SPC per DIN 7753) are preferred over classical profiles for new drive designs due to higher power density, smaller pulleys, and lower weight. In Mexico and LATAM, belts sold as "metric" or "perfil estrecho" follow DIN 7753 / ISO 4184 specifications. Major belt manufacturers (Optibelt, Continental, Gates) reference both DIN and ISO in their catalogs.