A spanner, often known as a wrench in American English, is a hand tool used for tightening or loosening bolts and nuts. Spanners are essential tools in various industries, including automotive, construction, and manufacturing. They come in various types and sizes, designed to fit different fasteners, ensuring efficient and secure fastening processes. This article explores what a spanner is, the types available, its uses, maintenance tips, and how it relates to other tools and materials like geomembrane in construction projects.