What are Open Ended Spanners? An Open Ended spanner is a tool used to tighten or loosen nuts and bolts or any other fasteners. How do they work? A spanner provides the user with increased grip and torque when turning fasteners. Some have one head and some have two heads ranging in size as well as the tool length. The longer the tool, the bigger the head to give the user more leverage. Features and Benefits Can be used on most types of fasteners Versatile Different sizes to suit your needs Ideal when working in confined spaces Where would you use them? Industry Workshops DIY enthusiasts Home Use