Full definition
Power transmission belt with a trapezoidal cross-section that wedges into matching pulley grooves, transmitting force through sidewall friction. The wedging action multiplies the effective friction coefficient by 3-5x versus a flat belt. Classic profiles per RMA IP-20: A (13 mm top width), B (17 mm), C (22 mm), D (32 mm), E (38 mm). Metric profiles per ISO 4184 / DIN 7753: SPZ (10 mm), SPA (13 mm), SPB (17 mm), SPC (22 mm). Narrow profiles (3V/5V/8V per RMA IP-22) transmit up to 3x more power per belt than classic. Efficiency: 93-98%. Max speed: 25-30 m/s. Life expectancy: 15,000-25,000 hours. Brands: Gates, Optibelt, Continental, Mitsuboshi, Bando.