The spanner is one of the most used hand tools in every home and workshop. It is used to tighten or loosen fasteners like nuts and bolts. They offer a tighter grip and amplify the mechanical pressure applied while turning objects. A spanner is also referred to as a wrench.
The market has both double-end spanner and single-end spanner. At the end of the metal shaft, the tool may either have one head or two heads on both sides. This head, or the jaw, is the part that fits over, around or into the fastener to grip it. The opening of the jaw is known as the spanner’s profile which makes contact with the fastener. Typically, the spanner profile has a fixed size, meaning it can fit only one size and shape of fastener.
Depending on the various profile shapes, spanner can be of many different types. They may also be categorized as per their specific purpose. Spanners are widely used for a variety of applications.
The most common types of spanners are:
- Open-ended spanners
An open-ended spanner comes with a U-shaped jaw where the width of the opening is same as the nut or bolt head. The profile has two flat sides which grip opposite sides of a fastener in order to loosen or tighten it. A double-end spanner is more common in the market, with a different-sized opening at each end. They are versatile and the same tool can be used for two different sizes of nuts and bolts.
- Ring spanners
The ring spanner has an enclosed opening that grips the faces of the bolt or nut making them less likely to slip. This again is a double-end spanner with a different-sized opening at each end. The heads are usually offset from the handle at an angle to improve access to the nut or bolt.
- Combination spanners
The combination spanner is a double-end spanner with an open-ended head on one side and a ring head on the other side. This is a combination of the open-ended spanner and ring spanner. Typically, both the profiles are of the same size, so they can be used for the same fastener size. This is the most common type of spanner found in a household.
- Flare nut spanners
The flare nut spanner also has an enclosed loop profile, similar to a ring spanner. But the profile has a tiny opening cut into them. Designed for turning nuts and bolts that are attached to tubes, they are used to work on plumbing pipes or vehicle brake pipes. The tube fits through the opening of the spanner and the spanner can then be slipped over the fastener’s head as normal.
- Ratchet spanners
The ratchet spanner can either be open-ended or ring spanner that works on a ratchet system mechanism. It allows the fastener to be turned in one direction but not the other while working. So, the spanner can be turned back and forth repeatedly without having to remove the spanner from the head after every turn. This makes the spanner work faster.
The podger has a profiled head at one end and a tapered spike at the other. The spike, or the drift pin, is pushed into the bolt holes of two workpieces to line them up so a bolt can be passed through the holes without being forced and damaged.
- Box spanners
Box spanners are made from metal tubing. They are mostly a double-end spanner with two profile heads on each end of the tube. Box spanners have a hexagonal profile, and they cover the whole of a fastener head. A ‘tommy bar’ is usually used to turn them.
- Pin spanners
Pin spanners are specifically used for turning lock nuts. A lock nut features two holes on opposite edges of the nut. The pin spanner grips the lock nuts by inserting two metal pins into the two holes. When the spanner is turned, the moving pins cause the fastener to move too.
- Flex-head spanners
The flex-head spanner features a flexible head that swivels to different angles. The head is in a stirrup, which allows the spanner to be used at different angles, increasing the reach of the spanner. The stirrup is made from the base of the head or the end of the shaft.
- Scaffold spanners
The scaffold spanner comes with a box-shaped socket head on one or both ends. They are designed for fitting and taking down scaffolding used for building work.