Spanners and wrenches are among the most essential tools in any DIY toolkit, yet many homeowners own only a single adjustable spanner and wonder why it slips or rounds off bolt heads. Understanding the different types available and knowing which one suits each task makes a significant difference to both the quality of your work and your safety. Whether you are tightening a loose tap, assembling flat-pack furniture or repairing a leaky pipe, the right spanner saves time, prevents damage to fixings and reduces the risk of injury.
Open-Ended, Ring and Combination Spanners
The most common hand spanners found in DIY toolboxes fall into three main categories. Open-ended spanners have a U-shaped opening at one or both ends, with each end fitting a different nut size. They are quick to slip onto a fastener from the side and are ideal for accessible fixings. However, because the grip covers only three of the six flats of a hexagonal nut, they are more prone to slipping under high torque, especially if slightly oversized.
Ring spanners have a fully enclosed head that fits completely around the nut. The head contains six points (hexagonal) or twelve points (bi-hexagonal). A six-point ring gives a firm grip with less risk of rounding the nut, while a twelve-point ring engages at more angles, which is useful in tight spaces. Ring spanners are preferred for stubborn or corroded fasteners because they distribute force evenly around the nut. Combination spanners offer the best of both worlds: one end is open-jaw and the other is a ring of the same size. Use the ring end to break a tight fastener loose and switch to the open end for speedy removal. Combination spanners are the most versatile choice for DIY work and are widely sold in metric sets from 6 mm up to 24 mm.
When selecting hand spanners, look for chrome vanadium steel with a satin or chrome finish. This offers good corrosion resistance and makes cleaning grease easier. A mid-range set from a reputable supplier serves most DIY needs for many years.
Socket Sets and Ratchet Mechanisms
Socket sets are collections of ring-type sockets that attach to a ratchet handle. Each socket is a cylindrical sleeve that fits over the nut, with a square drive hole connecting to the ratchet. Sockets come in six-point and twelve-point configurations, with the same trade-off: six-point for maximum grip and twelve-point for convenience in tight spaces.
The main advantage of a socket set is the ratchet mechanism, which allows you to tighten or loosen a nut without removing the socket between turns. As noted in many practical DIY guides about hand tools, a ratchet is one of the most labour-saving innovations in the workshop. Socket sets typically include sockets in common sizes, a ratchet handle, a sliding T-bar and extension bars that reach recessed bolts. Many sets also include a universal joint for driving sockets at an angle, which is invaluable for awkward fixings behind bathroom fixtures or on engine manifolds.
Budget socket sets are fine for occasional use, but for regular DIY work invest in a set with a finer-tooth ratchet and impact-grade sockets. Deep sockets are also helpful for working on plumbing connections and pipe fittings with long threaded sections.
Adjustable Spanners and Basin Wrenches
Adjustable spanners have a jaw that widens or narrows by turning a thumb screw on the handle. Their main appeal is convenience: one tool fits many sizes. However, the adjustable jaw never fits as snugly as a fixed spanner, and under heavy torque it can loosen and slip. This slipping is not only frustrating but can also cause injury if your hand strikes an adjacent surface.
Adjustable spanners are still useful for holding a bolt head steady while you tighten the nut with a second spanner, or when working with non-standard fasteners. For best results, adjust the jaw to fit as tightly as possible and apply force in the direction that pushes the movable jaw against the nut. For modern construction projects that use various fastening systems, an adjustable spanner is a practical backup to keep in your toolbag.
Basin wrenches are specialist tools designed for reaching and turning the back nuts that hold taps onto basins and baths. These nuts sit in tight spaces behind sanitaryware where ordinary spanners cannot fit. A basin wrench has a long shaft with a pivoting jaw at one end and a T-bar handle at the other. The two common types are:
- Cast-iron basin wrench with a fixed C-shaped jaw and a screw mechanism that tightens onto the nut
- Adjustable tap wrench with a sliding T-bar and interchangeable heads for different nut sizes
Both types are inexpensive and will save considerable frustration when replacing taps. If you are planning any bathroom renovation work involving ceramic tiles and fixtures, a basin wrench is one tool you should not ignore.
Pipe Wrenches, Strap Wrenches and Locking Pliers
Pipe wrenches, also called Stillson wrenches, are heavy-duty tools designed for gripping and turning cylindrical objects such as steel pipes and large fittings. The serrated teeth on the jaws bite into the pipe surface, and the more force you apply to the handle, the tighter the grip becomes. This self-tightening action makes the Stillson wrench highly effective for breaking loose rusted pipe joints.
Strap wrenches use a fabric or rubber strap that wraps around the workpiece instead of metal teeth. As you turn the handle, the strap tightens around the object without marking or damaging the surface. This makes strap wrenches ideal for chrome-plated pipes, polished fittings and decorative plumbing fixtures. They are commonly used in both plumbing and automotive work where preserving the finish matters.
Locking pliers, widely known as Mole grips, have a screw-adjusted jaw that locks onto a fastener with a cam-over action, holding it firmly without continuous hand pressure. They are excellent for gripping rounded-off bolt heads, holding two pieces of metal together while welding, or clamping broken fasteners for removal. For general workshop tasks involving cutting and clamping materials, locking pliers are a valuable addition to any toolkit.
Other specialist wrenches include:
- Box spanners tubular steel tools with six-sided heads at each end, typically used for removing spark plugs or accessing recessed nuts
- Immersion heater spanners large box-type tools designed for removing and installing electric heater elements in hot water cylinders
- Ratchet spanners a hybrid of a spanner and a ratchet socket, allowing the nut to be turned without removing the tool
How to Use Spanners and Wrenches Safely
The most important rule when using any spanner or wrench is to pull it towards you rather than pushing it away. Pulling gives better control and prevents your hand from slamming into an obstruction if the fastener breaks loose. If you must push, use the palm of your hand with an open hand so that if the tool slips your hand does not get trapped against the work surface.
Always use the correct size spanner for the fastener. An oversized spanner will round off the corners of the nut, turning a hexagonal head into a useless rounded shape. If a fastener is already damaged, locking pliers or a nut splitter may be your only option. For more advice on this topic, see our guide on techniques for removing stripped screws and bolts.
Keep your spanners clean and dry. Grease and oil on the handle reduce grip and increase the chance of slipping. A spanner with a worn or rounded jaw should be replaced immediately. Store tools in a dedicated roll or organiser so you can always find the correct size quickly.
Never use a spanner as a hammer, lever or punch. Spanners are hardened for torsion, not impact, and misuse can cause them to crack or shatter. Do not extend the handle with a pipe for extra leverage unless the spanner is specifically designed for it. Overloading a spanner this way can cause catastrophic failure. For more advice on selecting the right fasteners for heavy-duty construction connections, refer to our dedicated guide.
| Spanner Type | Best Use | Key Advantage | Common Limitation |
|---|---|---|---|
| Open-ended | Quick fastening in accessible spots | Slips onto nut from the side | Prone to slipping under high torque |
| Ring spanner | Stubborn or corroded fasteners | Full grip around the nut | Must be placed over the end of the nut |
| Combination | General purpose DIY work | Ring breaks loose, open end removes | Bulkier than dedicated open-ended spanner |
| Socket set | Multiple fasteners, ratcheting action | Speedy removal without repositioning | Needs clearance above the nut |
| Adjustable | Holding bolts, non-standard sizes | Fits many sizes with one tool | Jaw can loosen under heavy load |
| Pipe wrench | Steel pipes and large fittings | Self-tightening serrated grip | Damages pipe surface |
| Strap wrench | Polished or chrome surfaces | Grips without marking | Limited maximum torque |
| Basin wrench | Tap nuts under sinks and basins | Reaches confined spaces | Specialised, limited use |
| Locking pliers | Gripping rounded bolts, clamping | Locks on without hand pressure | Not primarily a turning tool |
Understanding which spanner or wrench to use for each task makes your DIY projects safer and more efficient. Start with a quality combination spanner set and a medium socket set as your core toolkit. Add specialist tools such as an adjustable spanner, a basin wrench and locking pliers as your projects demand them. Learning the strengths of each tool is an investment that pays back every time you pick up a spanner.