Wrenches are used to tighten and loosen fasteners, mainly nuts and bolts. Wrenches are generally made from a chrome-plated steel alloy. The material makes wrenches both durable and simple to clean.
While many people only keep one or two general-use wrenches around, there are actually many different types of wrenches created to serve specific purposes.
Wrenches are often named for their purpose, so you may be able to easily match the types of wrenches you need to the job you are trying to complete. This guide will teach you to recognize various types of wrenches and the jobs they are best suited for.
Main Types of Wrenches
There are several categories of wrench, mainly identified by the shape of the wrench end.
Open-End Wrench – A double-ended wrench with a U-shaped head at each end, open-end wrenches are used for nuts and bolts that are hard to reach. The design allows the user to approach the fastener from two different directions. One head is also a slightly smaller than the other, allowing you to work on bolts of slightly differing sizes with one tool. These wrenches are also usually sold in both standard wrench sizes and metric.
Box Wrench – These wrenches have closed loops at each end that are designed to accommodate both hex bolts and square bolts. They are usually sold in sets, and the better models may have a slightly offset design. Offset wrenches allow the heads to get a better grip on recessed nuts.
Combination Wrench - If box wrenches and open-end wrenches had children, the combination wrench would be the result. One side is a closed loop for hexagonal or square nuts, while the other end is an open U-shape. Used most often for difficult nuts, the closed end loosens the nut so that the open end can be used to quickly unscrew it.
Adjustable Wrench – The adjustable wrench is one of the most common types of wrenches in household use. Also called a crescent wrench, it has a single open end with a crescent-shaped jaw that opens or closed with the turn of a spiral screw in the head. Because the wrench is adjustable, it can take the place of a set of open-end wrenches, making it a space-saving choice.
Socket Wrench - Socket wrenches allow you to adjust nuts and bolts without repositioning the wrench. It uses a drive mechanism similar to a ratcheting wrench; if the wrench meets resistance, you can reverse the direction and then continue tightening or loosening the fastener.
Specialty Wrenches for Auto Repair
Lug Wrench – A lug wrench is used to remove or install tire lug nuts. They are often used on the go in fixing a sudden flat tire but can also be found in auto repair shops. The tool is cross-shaped with a socket of different sizes at each end.
Impact Wrench – An impact wrench looks a lot like a power drill. There are two styles; cordless impact wrenches use a rechargeable battery, while an air impact wrench operates with an air compressor. This tool is used to remove and attach nuts from tires quickly. An impact wrench is ideal for jobs that require very high torque and power, such as replacing multiple tires.
Strap Wrench – A strap wrench employs an adjustable loop attached to a sturdy handle. The loop may be made of rubber, chain or metal depending on the usage. The purpose is to grip and turn oil filters in automotive repair. However, the strap wrench can also be used in plumbing repair, to open jars and in any task where the grip point is much larger or broader than an ordinary wrench can accommodate.
Spark Plug Wrench – This type of double-ended wrench with a T-bar handle is used to adjust spark plugs in combustion engines such as in cars and lawnmowers. They are often sold as part of a kit with other automotive tools.
Fan Clutch Wrench – The wrench used to remove a fan clutch is a single-end wrench, flat with a U-shaped head.
Torque Wrench – When a very specific force has to be applied to a fastener, a torque wrench is the tool for the job. The tool is a version of a socket wrench that has very carefully calibrated internal works. They are used often in automotive work, particularly on engine repair.
Flare Nut Wrench – Similar to a box wrench, a flare nut wrench is double-ended, but instead of a fully closed loop, the ends have five sides. The one open side allows the wrench to loosen and tighten hex nuts that are used as coupling for a tube with reduced chance of damage.
Specialty Wrenches for Bike Repair
Spoke Wrench - A spoke wrench is usually a small disc-shaped wrench with a slotted end that fits around the spoke itself and an open end that turns the spoke nut. They are used to adjust the tension of the spokes. Spoke wrenches are mainly seen in bike repair, though they can be used on other objects with wire wheels.
Dog Bone Wrench – The dog bone wrench is named for its shape. The wrench is a double-ended box wrench with each end having a different socket size. The wrench is designed to fit into tight spaces, making it ideal for bike repair.
Pedal Wrench - A dual-sided wrench with a U-shaped indention in each side, the pedal wrench is used to repair bike pedals.
Cone Wrench – A cone wrench is a double-ended, open-end wrench. It is very thin and flat, making it extremely useful for turning bolts or fittings in areas that have little to no clearance. While they are primarily used in bike repair, cone wrenches have been used to adjust leveling nuts on large appliances such as a washer or refrigerator.
Specialty Wrenches for Plumbing
Pipe Wrench – A pipe wrench is used for turning metal pipes and fittings. It has an open end with an adjustable jaw to allow it to be sized for pipes of various diameters.
Basin Wrench – A basin wrench has a long, thin handle affixed to a pair of asymmetrical jaws joined by a pin. The wrench is designed to reach fittings in very recessed areas that one could not reach with a standard pipe wrench.
Garbage Disposal Wrench – A garbage disposal wrench is typically designed with a long shaft and a wide flat head that pivots easily. It’s mainly used to remove the nuts that affix a garbage disposal to its assembly and can also be used to fix cutter plate jam
Other Specialty Wrenches
Hex Key – This wrench is called a hex key due to the hexagonal shape of the body. The metal shaft may end in an L-shape or T-shape that serves as a handle to better be able to turn the wrench. They can also be found as a set that extends from a single case where several wrench sizes are collected together for ease of use. Both standard and metric wrench sizes are available.
Torx Key – A Torx key wrench is similar to a hex key. It’s usually sold in sets with varying sizes, and features an L-shaped handle to allow ease of grip and turning. Torx keys, however, are designed to fit a specific start-shaped depression rather than the hexagonal one that matches the Allen wrench.
Crowfoot Wrench – A crowfoot wrench has a head with a single open end and no handle. They are usually sold in sets. The crowfoot wrench head attaches to a torque handle; it is designed to fit at the side of the fastener rather than over the top. This lets the wrench operate as a socket wrench in spots where there isn’t enough clearance to use a standard socket wrench.
Standard wrench sizes usually have equivalent metric wrench sizes and can be used interchangeably to accommodate the same size bolt. For example, a 10 mm wrench in metric is equivalent to a 3/8-inch standard size and both fit a 3/16-inch bolt. Wrench kits are a convenient way to get an array of organized, commonly needed wrench sizes from smallest to largest.
Usage and Safety Tips
- Wear gloves and safety glasses when using wrenches or other tools.
- Always keep wrenches in good condition. Clean and dry your wrenches before returning them to the tool box after use. Replace any that are damaged or broken.
- Select the correct wrench for the type of job you intend to do.
- When using a wrench, only apply a small amount of pressure at first. Once the fastener begins to loosen, you can apply a greater force.
- When using an adjustable wrench, position the tool so that you are turning the fastener toward your body. This improves your leverage.
Any good tool box should contain different types of wrenches. As you take on different home and DIY projects you will naturally build your collection of wrenches and, with good maintenance, eventually you’ll find that you have the right wrench sizes and types of wrenches for last minute fixes at your fingertips. Once you’ve learned all about types of wrenches, you can check out our other buying guides to discover more of the tools you need to fill out your tool box.