Combination Spanners

Combination spanners have an open end on one side and a polygonal ring end on the other. The open end slips onto the nut from the side, while the ring end wraps around it and lets you apply the final force without slipping. They are basic tools in workshops, maintenance and on site, because they cover most jobs involving common nuts and bolts.

A standard combination spanner has a fixed head: it has to be taken off and repositioned on the nut with every turn. The ratcheting head version lets you tighten or loosen without removing the spanner, saving a lot of time on repetitive jobs. The plain combination spanner remains useful when you need a secure fit and constant force, and to add to a set.

Choose the sizes according to the nuts and bolts you need to work on. For general use, start with the most common sizes; the catalogue includes single spanners from 8 to 19 mm to complete a set. Sets supplied in a case, on a holder or in a thermoformed tray list the sizes included, so you can see at once whether they cover your work.

Always choose the exact size for the nut, because a spanner that is too large will round it off and ruin it. Slip the ring end over the nut, check that it is seated properly and pull with a slow, steady movement. Do not extend the handle with pipes to gain more force: for very tight nuts, use a suitable tool rather than the spanner.

Where sparks or flammable vapours may be present, non-sparking spanners are used; they are made from materials that do not produce sparks when struck. The catalogue includes model 42BA. Before use, check the manufacturer's instructions and make sure the spanner is suitable for the working environment. Ordinary steel spanners are not designed for these areas and must not be used in their place.

The finish mainly affects appearance and corrosion resistance in damp environments. Chrome-plated spanners are shiny and easy to clean, while satin ones have a matt look. In workshops the choice depends on how long the tool stays in contact with oil and moisture, and on the look you prefer in the workshop.

The brand matters less than the type of work. For heavy use on site, look at the finish, the strength of the ring end and whether the set comes in a case, which protects the sizes from dust and moisture. To add to a set you already use, the same brand is best, so that dimensions and finish match. The catalogue includes Fervi, Stanley, Makita, Milwaukee, DeWalt and Efco.

Put the spanners back in the thermoformed tray, case or holder supplied with the set, with the sizes in order, so that each spanner returns to its place. Keep the set in a dry place and wipe the spanners after use with a cloth, to remove oil and dust that could encourage corrosion. A lost spanner is easier to track down if the set is complete and kept in order.