Leco A Global Leader in High-Quality Analytical Instrumentation, Mass Spectrometers, Metallography/Optical Equipment, and Consumables. Over the past 75 years, customers around the world have trusted LECO to provide analytical solutions for a variety of applications and markets, including mined materials and metals, environment and agriculture, energy and fuels, foods and beverages, and life sciences (pharmaceuticals, metabolomics, forensic science/toxicology, and flavor/fragrance analysis).