homespannersspanner-basics Spanner Basics Chris 1st January 2019 733 Views SaveSavedRemoved 0 Spanner basics Shop for Spanners A spanner is a small, fixed-size hand tool designed to tighten or loosen fasteners (holding two or more workpieces together) by turning a nut or bolt. Spanners can be made from a single piece of metal… …or have joints and extra components. Lots of different sizes and shapes are available for all sorts of different jobs around the home and across the industries. Spanners can be purchased singly or in sets.