Spanners are one of the most common hand tools found in any tool bag, box or kit and are used for fastening and loosening nuts or bolt heads with a hexagonal shape. They are typically made from hardened chrome vanadium steel or beryllium copper, and the most common types can comprise of a ring-style spanner on one end and an open jaw spanner on the other (a combination spanner), or two open jaw ends (an open-ended spanner).The ring end recess, if present, is generally a six-point or twelve-point opening and sometimes offers a ratchet mechanism that helps apply maximum force with minimal user effort. This will most likely match the size of the open jaw end, but always check each tool. The open jaw is typically offset by 15 degrees to allow for a greater freedom of movement during operation, which also allows a higher torque force to be applied to help turn the chosen fastening.Spanners are available in a variety of metric (mm) and imperial (in) sizes to allow for greater functionality across a wider range of applications. Our range includes products from leading brands such as Bahco, Facom, Ega-Master, Stanley, Wera & RS PRO.How do spanners work?In the case of open jaw spanners, these tools work by holding the opposite sides of a nut or bolt to channel the physical movement of the user, applying torque force to the fastening so that it can be turned. The same rules apply to ring-style spanners, the only difference being that the ring fully encases the fastening rather than applying force to opposite sides. Depending on the material they are made from, spanners can often withstand large amounts of torque being applied to stubborn fasteners.Type of spannersCombination Spanners – A combination spanner will have the open jaw spanner on one end and the ring-style spanner on the other.Open Ended Spanners – As the name suggests, these tools have an open jaw at each end, however they often differ in size.Ratchet Spanners – Ratchet spanners allow the angle of the tool to be adjusted by the user without removing it from the fastening. Also known as socket wrenches: view our range in our socket wrenches section.Ring Spanners – Ring-style spanners have enclosed openings to grip the complete fastening rather than just opposite sides. Double ended ring spanners often have offset handles to improve access to nuts and bolts.C Spanners – Also known as hook spanners, these are high-quality tools designed to loosen retaining rings and adjusting chains. View our range of C Spanners hereWho uses spanners?Spanners are used across many industries, including:AutomotiveAerospaceConstructionManufacturingDIY