Spanner Sets Guide: Types, Sizes & How to Choose

Ratchet spanner sets are often among the more expensive types of spanner kits, but their handy added functionality makes them easily one of the most popular designs found in both professional and enthusiast tool kits.

The main advantage of a ratchet spanner over a non-ratchet or regular type spanner is that, where space for a full rotational arc is limited, they don’t need to be removed from the nut and realigned in between turns. The ratcheting mechanism allows for free rotation of the spanner in one direction but not in the other - this means you can tighten a nut clockwise, for example, and then pull the spanner back in an anticlockwise direction to begin another clockwise rotation without ever lifting it off the fitting.

Nearly all ratchet-type spanner sets will allow this feature to be deployed in both directions, either by flipping the spanner over or by adjusting a small lever on the handle or head of the unit. Spanner ratchet sets are usually sold in open-ended, flare or ring head configurations, depending on the types of fixtures you need to tighten or loosen.

The tooth count of the ratchet mechanism is worth checking before you buy. A standard ratchet typically offers 30 to 45 teeth, requiring 8° to 12° of swing per click; a fine-tooth ratchet of 72 teeth or more needs as little as 5° of swing to advance. In confined spaces such as engine bays, behind dashboards or between frameworks where only a few degrees of arc are available, the fine-tooth design is a genuine workshop advantage and is the preferred specification for serious automotive and mechanical work.

A box spanner set - sometimes called a tubular spanner set - is easily identifiable due to the elongated cylindrical shape of the tools. These kits are essentially designed as a variety of rounded metal tubes, usually with a hexagonal opening at each end to be placed over a nut. As a result, they contact all sides of the nut, providing a stronger grip than most jaw-type spanners.

By passing a metal rod (a ‘T-bar’ or ‘Tommy bar’) through two holes positioned across the diameter of a box spanner, users can rotate the tube in a one- or two-handed motion, similar to opening a tap. Most box spanner sets are sold with a suitable T-bar already included, although it is possible to buy replacements separately (you’ll need to check the correct gauge for your spanner set first).

The elongated shape of box spanners makes them very handy for accessing nuts that are deeply recessed or otherwise in difficult-to-reach places, and the sliding design of most Tommy bars lets users make best use of any available space for achieving sufficient torque.

A ring spanner set functions much like the box spanner sets described above, except that ring spanners are designed in a more standard spanner layout; that is, they’re generally constructed as a single-piece metal bar that turns side-on to a nut, rather than from above. The ring spanner’s connection with a fastener is very similar to that of a box spanner. The heads on a ring spanner set - each piece usually has a head at each end - are formed as a single closed loop containing a machined profile, which contacts the nut on all sides simultaneously. This offers a very strong grabbing force and makes it less likely to slip.

The potential downside of ring spanner sets is that the tools must be lifted and replaced on the fastener once the full turning arc has been exhausted. However, they can often be manoeuvred into smaller spaces than box or socket spanners, particularly if the design features a ‘cranked’ or offset head design.

A practical buyer consideration here is the profile of the ring: 6-point versus 12-point (bi-hexagonal). A 12-point ring repositions on the nut every 15° of rotation, making it the easier choice in confined spaces where you cannot swing a full 30°. A 6-point ring repositions every 30° and contacts the nut on the flats rather than the corners, distributing load across the fastener faces. For extreme torque or for nuts already damaged or rounded, the 6-point profile is the preferred choice; for general-purpose work in tight spaces, the 12-point earns its place.

A socket spanner set essentially offers the same functionality as a box spanner, except the kits tend to come as a single spanner shaft with multiple interchangeable heads or sockets. These too contact the fastener on all sides, but the torque is applied via the shaft, as opposed to a Tommy bar.

The shaft or ‘key’ will feature a small recess (or sometimes protrusion) known as a drive socket at the head end - usually square or hexagonal - into which the various differently sized sockets fit. Drive sizes are standardised: 1/4" drive suits small fasteners and light work, 3/8" drive covers most general automotive and workshop tasks, and 1/2" drive handles heavier industrial and structural fasteners. Matching the drive size to the work is the first decision in choosing a socket set; you can read more in our socket sets guide.

Socket and spanner sets very often feature a ratchet system, meaning they don’t have to be lifted off the nut between turns. Socket and ratchet spanner sets are available for almost any type of nut or fastener, so it’s important to check you’ve got the right setup for your needs when purchasing a kit of this kind.

Spanner combination sets, as the name implies, tend to offer a wider range of head types for tackling various sorts and sizes of nut and fastener with a single tool kit. They are the most common spanner type found in Australian toolkits, and the parameters of any given combination kit will vary widely among different manufacturers and product lines.

A particularly common configuration for spanner or wrench combination sets is a kit that offers both ring spanner and regular jaw-type functionality, either as two separate collections within the same box or as a single set with different head types at either end. A metric combination set covering 6 mm to 24 mm handles the great majority of fasteners encountered in Australian automotive, construction and industrial maintenance work, which is why it is the most widely recommended starting point for a tradesperson's first complete spanner set.

For users likely to work in confined or awkward spaces, ratchet combination spanner sets (with a ratcheting ring end) add another layer of convenience over the basic combination design.The best combination spanner set for your needs will of course depend entirely on the application you’re intending to use it for.

An imperial spanner set, rather than denoting a particular function or a specific type of head or shaft design, is simply a spanner set of any kind that has been constructed for fasteners defined by imperial measurements (inches and fractions of inches, rather than millimetres). Australia metricated through the 1970s, so most modern fasteners on the local market are metric, but imperial spanners still earn their place in several genuine Australian use cases: pre-mid-1970s Australian-built vehicles, American agricultural equipment such as John Deere and Case IH tractors and harvesters, and imported US-built industrial machinery and plant.

If you are servicing any of the above, an imperial spanner set is not optional; metric spanners will not fit the fasteners cleanly and using a near-size metric spanner on an imperial nut is a fast way to round the corners. Imperial sets are stocked in both ring-type and jaw-type configurations to match the application.

Metric spanner sets are designed to tackle nuts and fasteners defined by millimetre sizing and are the default standard for all modern Australian applications. Metric became the dominant fastener standard across Australian automotive, construction, plumbing and engineering work progressively through the 1970s and 1980s, and today the metric set is the kit a tradie reaches for first.

Spanner metric sizes for general trade work span 6 mm through to 32 mm and beyond, available across all the standard formats: metric combination spanner sets, metric ratchet spanner sets and metric ring spanner sets, with the configuration chosen for the flexibility and functionality your work demands.

Adjustable spanners typically feature a standard layout open-ended head design, but with an additional function that allows for manual opening or closing of the spanner’s jaw via a rotating thumb-wheel driven by a screw. In Australia, adjustable spanners are universally referred to on site as "shifters". The familiar ‘monkey wrench’ design is essentially a type of adjustable spanner, although many tools can be found in this range that are considerably smaller and lighter than a typical heavy-duty plumbing wrench.

The adjustable mechanism enables a single spanner to tackle numerous gauges of nuts and fasteners, which can be handy for smaller portable tool kits where it’s always helpful to save on space and carry weight. As a result, adjustable wrench kits usually include fewer pieces than non-adjustable sets, while covering a wider range of fastener sizes. Higher-quality adjustable spanners may also feature self-locking mechanisms that help prevent the jaw from loosening during use.

One critical technique point worth flagging clearly, because it is the difference between a clean job and a rounded nut. Always apply force to the spanner so that the load goes onto the fixed (lower) jaw, not the moveable (upper) jaw. If you turn the spanner so the force pushes against the moveable jaw, the jaw spreads under load, the spanner slips, and the fastener rounds. The correct technique is so consistent that it is worth getting right the first time, every time.

In terms of functionality, flare nut spanners offer a combination of features seen on both ring spanners and standard jaw spanners. They offer almost the same tight-gripping multi-surface contact as a ring spanner, except they feature a cutout portion in the circumference of the head loop - this is usually offset by 15 degrees, making the flare spanner look similar to a jaw-type spanner from a distance.

The cutouts on a flare nut spanner set allow the head to be placed over fasteners that are permanently attached to a hose or tube - this wouldn’t be possible with a full ring head. In sacrificing contact with one of the six sides of a nut, the flare spanner gains the ability to access fittings such as brake line unions, fuel line connections and A/C refrigerant lines.

In Australian automotive work, the typical fastener sizes are M10×1.0 and M12×1.0 metric brake line unions, fuel line fittings and A/C line connections, all of which round catastrophically easily under an open-end spanner. The safety rule is straightforward: never use an open-end spanner on a brake or fuel line fitting when a flare nut spanner is available. The few extra surfaces of grip are the difference between a clean service and a damaged fitting that needs replacement.

A flexible spanner, often shortened to flex-head, denotes an additional feature of some ratchet or socket tools that allows for the head of the spanner to swivel through a range of positions and angles. In practical terms, this simply means that a flexible head spanner set can be used to access fasteners in a much wider variety of tricky or confined spaces, because the user can approach the nut from a much broader array of positions.

Widely used in plumbing and automotive settings, any spanner type can have a flexible design, although flex-head ratchet spanner sets and flex-head socket spanner sets are among the more popular product types in this range. It’s also common to find combination spanner sets with flexible heads.

Open-ended spanners are the archetypal spanner type: the simple, often one-piece jaw spanner that’s useful in all manner of applications. In this design, two opposing jaws are set in a fixed and open position at varying distances/gauges apart, depending on the size of spanner in question. As a cost-effective utility tool, most open-ended spanner sets will offer a wide range of sizes and gauges in a typical kit. Sizes might range from 4mm to 50mm (5/32" to 2"), and handle lengths can vary enormously, ranging from 10 cm to 50 cm or more.

One key limitation is worth understanding clearly. An open-end spanner contacts the fastener on only two faces of the hex, which means high torque concentrates the load on two points of the nut rather than across all six. Under heavy break-out or final tightening forces, this is exactly the situation that causes the spanner to slip and round the corners off the fastener. Treat the open-end spanner as a run-down and access tool, not a break-out tool. When the nut is tight or stuck, use a ring spanner or a socket; when it is just being turned along the thread, the open-end is the quick choice.

An insulated spanner set might feature any of a range of head types and additional functions for various intended applications, but what they all have in common is that they’re intended specifically for use with fasteners in electrical components or circuits.

Insulation against electric shock is usually achieved through a plastic or rubber coating applied across the full length of the insulated spanner handle (and sometimes around the head itself). Quality tools certified to IEC 60900, adopted in Australia as AS/NZS 60900 (Hand Tools for use on live or near-live electrical installations), are rated for safe use on live wires up to 1000 V AC. Confirm the certification mark on the tool before use, and inspect the insulation for cuts, abrasions or damage before each electrical task.

Bahco is a leading name in professional-grade tools, with a reputation for design and manufacture that meets exacting user standards for ruggedness, performance and ergonomics. Bahco combination spanner sets are available in open-ended, ratchet and adjustable configurations, to name just a few.

Facom is a France-based brand name recognised worldwide. It’s known for high quality tools that get the job done at a highly competitive price, and its combination spanner sets are popular choices for both home users and professionals due to their simplicity of use and solid design mechanics.

Gearwrench is a US company that has quickly become the go-to name for many professional automotive mechanics. It made its name with the patented five-degree ratcheting wrench in the mid-1990s, and Gearwrench spanner sets are used widely today with an excellent reputation for speed, strength and access.

Gedore started life as a German-based company in 1919, but expanded to full international operations during the 1960s and has since become one of the world's largest hand tool manufacturers. Gedore spanner sets, like most of their hand tools, are renowned for their sturdy build quality backed by considerable in-house expertise.

Wera is yet another German brand known for lasting quality and precision, but they’re also seen as one of the most innovative designers of hand tools on today’s market. They specialise in screwdriving and torque tools, including Wera spanner sets - and frequent innovations, such as the Zyklop ratchet and the Joker open-end wrench, have made them a go-to manufacturer for fans of cutting-edge, user-friendly design flourishes.

Stanley is, of course, a name that needs little introduction: its tools have been synonymous with reliability, innovation and value for over 170 years, making them one of the most popular brand names today among both hobbyists and professionals alike. Stanley spanner sets, like most of its extensive catalogue of hand and machine tools, are known for their ruggedness and consistency of build quality.