Next Day Delivery on 1000s of products

16 Types of Spanners and Their Uses

Set of spanners
23 March 2023 2858 view(s)

When doing DIY, the tools you use depend on the task at hand, and each tool has its own variations to suit your requirements. For example, whilst spanners are used to loosen and tighten fasteners, there are different types of spanners so you can find the shape and size you need. As a general rule, the larger the head size, the longer the spanner.

Find out about the types of spanners and wrenches available for your upcoming projects.

Types of Spanner

1) Single Open End Spanner

Single Open End Spanner

When establishing a spanner’s size, the distance between the two jaws is measured. Single open-end spanners have a head that can grip two opposite sides of a nut or bolt. If a fastener has two flat faces parallel to each other, the open-end spanner can turn it.

The spanner’s head is at a 15-degree angle to the handle, and it can be used for bolts with an octagonal, hexagonal or square head. This tool comes in numerous sizes, spanning 6mm-135mm, and can be between 92mm-50cm long.

For those working with electrical equipment, insulated variations are available. For example, the Bahco 21mm Insulated Open Ended Spanner can be safely used with up to 1000 volts and is double insulated. Alternatively, if you require spanners of multiple sizes, then consider an open-end spanner set.

2) Double Ended Spanner

Double Ended Spanner

The double ended spanner has two open-end heads, one at each end, and is the most commonly used spanner available. The ends are angled at 15-30 degrees, and the handle is both flat and slim. This tool is made for use with rotary fasteners.

For those requiring a double ended spanner, the Bahco 30mm & 32mm Double Ended Spanner is manufactured from alloy steel and has a phosphate coating to help prevent corrosion.

3) Box Spanners

3) Box Spanners

Most spanners of this kind are designed for hexagonally shaped nuts and bolts. The box spanner is a small metal tube with holes drilled at a perpendicular angle into the metal. The Tommy bar, also known as the T-bar, can then be inserted through the holes so the spanner can be turned. You need a Tommy bar to use the box spanner, as it enables you to turn the spanner like a tap.

This spanner usually has two profiles, which are found at either end, and these can be different. Most often, they have a hexagonal shape because this is the most common shape for fasteners. 

When in use, the box spanner fits over the top of the fastener, meaning it touches all edges of the nut or bolt, and the Tommy bar is used to tighten or loosen it. The spanner’s size can be measured in various ways, such as Whitworth, BA, metric and imperial AF (across flats) sizes.

If you purchase a singular box spanner, you will also have to buy a separate Tommy bar. The spanner you choose should mention which Tommy bar you need, whereas a box spanner set may include the one required. Insulated box spanners come with the T-bar permanently attached, enabling the spanner to be insulated properly to protect you from electrical currents.

One type available is the Stahlwille Box Spanner, which is a 17mm box spanner made from chrome alloy steel.

4) Combination Spanners

Combination Spanners

Sometimes a project requires multiple spanners. The combination spanner has two ends, one open-ended and the other looped. This loop is a ring spanner, and both ends of this tool fit onto the same size fastener. You can find them in sizes between 3mm-80mm, and the handle’s length increases with the size of the heads.

When buying this tool, you only get one size per spanner. However, you get access to two types as mentioned previously, which is why they can be considered a good value for money. Combination spanner sets enable you to have several of these spanners in various sizes.

The open end is stronger than the ringed end because it applies less pressure on the weakest parts of the nuts or bolts, which are thought to be the corners. It is also good for the first turns when loosening a fastener, or for the last turns to tighten one. In contrast, the looped end can be flexible, depending on the combination spanner, and can be ratcheted or non-ratcheted.

5) Crows Foot Spanners

Crows Foot Spanners

Unlike most spanners, the crows foot spanner has no handle. It is shaped like an open-end spanner but has no shaft, making it ideal for use where 6pt and 12pt spanners can’t reach. To extend the length, it can be combined with a ratchet, or to apply extra force, a torque wrench may be used. Crows foot spanner sets are also available.

There are variations of the crows foot spanner, including:

Adjustable Crows Foot Spanner

There are two versions of the adjustable crows foot, (the adjustable spanner and the self-adjusting spanner). The adjustable crows foot is for a larger bar size range than the open-end spanner. The self-adjusting crows foot contains an inner bar that is spring-loaded, which is worked by the flexible lever accompanying this spanner. This lever enables the spanner to fit tighter to the nut or bolt, meaning more force (torque) is applied to the fastener.

Flare Crows Foot Spanner

When working on fluid lines, such as the breaking system in cars, the flare crows foot spanner is ideal. It can also be used for the fluid lines connecting the hydraulic system with the vehicle’s drive.

Open End Crows Foot Spanner

This variation can fit with most holds, which is a unique quality of the open-end crows foot spanner. It is commonly used by auto mechanics and people who do DIY.

6) Pin Spanners

Pin Spanners

Also called pin keys, the pin spanner is mostly used when attaching grinder power tools and abrasive grinding pads together. It is used for fasteners called ‘lock nuts’, which have two holes in the head for the spanner’s pins to be inserted into. This enables the fastener to be turned. 

There are different designs which provide the same results, such as the adjustable pin spanner. Usually, a pin spanner contains a hole so it can be attached to lanyards or other tools. Others sometimes have an additional hole, which can be used for flat-sided fasteners.

When looking for the right pin spanner, two different sizes are usually given, and these are the distance between the central points of both pins and the diameter of the pins. The diameter tends to be between 2.9mm-10mm, and the distance between the pins is usually between 10mm-230mm.

7) Ratchet Spanners

Ratchet Spanners

These tools can have a ratcheted head at both ends or just at one end. The ratchet spanner is designed to move back and forth whilst only moving the fastener in a singular direction. This means the head doesn’t have to be removed and reattached to the fastener when loosening or tightening. Additionally, you can alter the direction the spanner moves in.

The ratchet spanner can be between 90mm-425mm long, with the length increasing with the size of the head, and the ratchet head sizes are between 4mm-36mm. However, if you need to reduce the size, some of these spanners have interchangeable heads or bushes that can fit onto a larger head size.

Ratchet spanner sets offer this tool in various sizes. You can also get spanners with two ratcheted heads, providing two sizes in the same tool. For example, the Stahlwille 11mm & 10mm Ratchet Spanner is lightweight and appropriate for heavy-duty usage.

8) Ring Spanners

Ring Spanners

This tool has a looped head to grip the fastener on all sides, meaning it’s less likely to slip off when used. Ring spanners are double-headed and can turn a fastener in wider arcs so it takes less time to loosen and tighten.

The most common type is the bi-hex, which contains 12 troughs and points to grip fasteners with. Bi-hex ring spanners can be found in ring spanner sets, such as the Stahlwille Deep Bi-Hex Ring Spanner Set, and can be used for square and hexagonal fasteners. They can also move into smaller spaces and lock into them. 6-point spanners can only be used for hexagonal fasteners.

These spanners can range between 100mm-750mm long, and they can fit onto hexagonal fasteners sized between 4mm-210mm. If you want to use a ring spanner for a square fastener, increase the size of the fastener head by 25%. This number is the size of the required spanner.

9) Slogging Spanners

Slogging Spanners

Designed to be used with a hammer, the end of the slogging spanner is thick to allow the fastener to be tightened to a specific torque. They are ideal to use if the fastener is stuck and needs loosening, and are usually sized between 24mm-210mm. 

The slogging spanner, also known as a hammer wrench, tends to be used for larger fasteners. The head has a block end and is stocky, short and thick to enable high force and shock.

Slogging spanners, such as the Bahco 100mm Slogging Spanner, tighten a nut after they are initially tightened manually. The fastener’s elasticity is established using index markers, and this works out the torque required.

10) Torx Spanners

Torx Spanners

If you have Torx fasteners, Torx spanners (or Torx spanner sets) can be used to loosen or tighten them. The head (or both heads) resembles a 6-point star and it is designed to not slip whilst tightening a fastener.  It should also prevent cam-out from the person using this tool when requiring heavy torque.

Heamar offer several Torx spanners, including the Stahlwille E20 & E24 Double Ended Torx Spanner, which is suitable for heavy use and is manufactured using chrome alloy steel.

11) Allen Key

Allen Key

This spanner tends to be bent to a 90-degree angle towards one end to form an ‘L’ shape and can be purchased individually or as part of an Allen key set. For example, the Klauke Folding Allen Key Set contains 7 keys with sizes ranging between 2mm-8mm. 

The Allen key is also called the hex key and is a thin steel rod with 6 faces. It is designed to fit a socketed head in a fastener and can tighten fasteners whilst the surface of the job remains equal. 

The shorter arm can fit into tight spaces, whereas the long arm allows more torque to be used, making installations and removals easier. This is one of the simplest tools for manipulating fasteners and can come with products such as flat-packed furniture.

12) T Socket Spanner

Made from forged steel, the metal for the T socket spanner has a protective coating to make it more durable. It is similar to the box spanner, but the handle at the top cannot be removed. 

This tool is available in numerous sizes and is used when there is a deep space between you and the fastener you want to access. The T socket spanner is comfortable and easy to use due to its ergonomic design and is normally used to loosen bolts and rail wrenches. 

13) Magneto Spanner

The magneto spanner is the ideal solution for small nut bolts. It is a collection of small, connected single-end spanners in different sizes that are usually distinguished via numbers, with 8 being the largest spanner and 1 being the smallest. 

Its small size makes the magneto spanner an ideal addition to any toolbox. They can also be called ignition spanners and are used when fixing and servicing magnetos. This tool tends to have a screwdriver attached.

14) Socket Spanner

There is a square hole at one end, which is where the Tommy bar can be fixed due to its square shape. At the other end of the socket spanner, there are grooves cut to the nut-bolt shape, much like the ring spanner, and it is shaped like a round socket. Socket spanner sets are available in both large and small sizes.

15) Hook Spanner

Hook Spanner

For fasteners that have no faces, the hook spanner is designed to tighten and loosen nuts with a periphery with no holes. For example, Stahlwille Adjustable 20mm-42mm Hook Spanner is an adjustable tool that ranges between 20mm-42mm and weighs 90g. 

A hook spanner is curved and has a hooked nose or a pin at the end, allowing it to grip the nut or bolt. This pin connects with the hole, enabling it to turn the fastener. This is a special-purpose tool that can be used on ring nuts and is often used to maintain motorbikes and cars.

16) Basin Spanner

Basin Spanner

This is a plumbing tool designed to use on fasteners for baths and basins. The basin spanner has two asymmetrical jaws connected to a long shaft, and there is a handle at the other end. As shown through the Bahco 10mm-32mm Basin Spanner, one of the jaws is curved and closes around the nut or bolt due to the jaw being spring-loaded. The other jaw is connected to a spanner. When someone turns the shaft, it applies torque to the fastener.

When completing your DIY project, you need to find the right tools to ensure you get the best results. Heamar have a range of hand tools available, including spanners, that could be a great addition to your toolbox.

Related posts