Wrenches are among those everyday tools that you might overlook until it’s needed. You may often grab whatever wrench is nearby to tackle whatever project you face. But there are actually quite a few different types of wrenches out there, and many are specially designed to handle a specific task.
Wrenches are generally either male or female. Male wrenches are inserted, much like the head of a screwdriver. Female wrenches have a socket which fits over or around the object they will be turning. Both are used to loosen or tighten nuts, bolts, screws, and even mechanical caps and casings.
The following 39 types of wrench encompass the gamut of styles and functions, although there are more wrenches out there that are extremely rare or specialized.
Classes of Wrench
There are a few common terms used to classify wrenches into subgroups. While knowing these terms will give you a better idea of a wrench’s purpose, they are all interchangeable with the broad term of “wrench” (example: Allen wrench vs. hex key).
Key – Keys are usually very specialized and most often appear as an old-fashioned key without teeth or as a T-shaped socket that may have a male or female tip. Allen wrenches, bottle openers, and window cranks are all types of key wrench.
Socket – Socket wrenches may refer to either a single piece or a handle which attaches to cylindrical sockets. The socket fits over the head and turns either vertically or horizontally, depending on the handle’s orientation.
Spanner – Spanners are wrenches used to turn a spanner head and have a design that has pins or hooks instead of a normal end. The term is most commonly used in British English to describe wrenches in general, although it has seen some use in the US as a subgroup of wrench. For more information, see below.
Common Wrench Types
Chances are, you have at least one of these somewhere in your home. The average toolkit will have several. Many of these wrenches will have a range of uses, as opposed to the less common ones discussed later.
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More commonly referred to as a crescent wrench, these are one of the most popular wrenches available. They have an open end with a spiral screw embedded that opens or closes the crescent as you turn it. For this reason, it can perform the same basic function as an entire set of combination or open-ended wrenches, although it requires more space due to its thicker size.
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Also referred to as a hex key, this hexagonal piece of metal may be either L-shaped or T-shaped with the extra limb functioning as a handle. As a male-style wrench, this fits into the heads of screws and bolts that have a hexagonal recess. Allen wrench sets usually come in either SAE or Metric sizes.
These wrenches have a closed loop at both ends, sometimes slightly higher or lower than the handle to let it grip recessed nuts without rounding the edges. The closed ends are designed to fit either hexagonal or square bolts, and are different in size. Box-ended wrenches are frequently sold in sets.
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If box-ended wrenches and open-ended 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.
These curious open-ended wrenches have no handle. Instead, the single head is designed to attach to a ratchet handle and socket extension, allowing it to fit into very tight spaces. They work great for handling bolts located deeper on a machine’s body when you don’t want to remove nearby parts first.
More closely resembling a power drill in appearance, air impact wrenches use an air compressor while cordless impact wrenches use a rechargeable battery. The former are sometimes called air wrenches or air gun. Part of the socket family, this wrench can apply high torque, making them a great choice for handling multiple nuts (such as when replacing tires), although they are a poor choice for any job that requires precision.
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This aptly-named tool has a large, cross-shaped design with four sockets of different sizes. They are used to tighten or loosen lug nuts on cars, earning them the nickname of “wheel brace”.
Oil Filter Wrench
Another tool used mainly in the automotive industry, oil filter wrenches actually have four different styles and often have to be matched to the brand of car. Chain strap and metal strap styles use a loop to wrap around the filter casing, while the more recognizable claw wrench functions similarly to an adjustable wrench. Finally, socket-style filter wrenches resemble a cup with parts of the sides cut away. These fit onto the bottom of a filter cap, and are used with a ratchet handle.
One of the most common types of wrench found in toolboxes, the open-ended wrench has two U-shaped ends, with one being slightly bigger than the other. They are used for hard-to-reach nuts and bolts, and the open design makes it possible to attach them either vertically or horizontally onto the target fitting. The downside is that they are more likely to round the edges of a nut than box-ended wrenches.
This is the big brother of adjustable wrenches, with a sturdier, F-shaped design. Used mainly by plumbers on metal pipes and fittings, the serrated jaws of this hefty tool can easily leave scratch marks behind.
Similar to open-ended wrenches, box-ended wrenches, and combination wrenches, a ratcheting wrench has at least one end which has a ratcheting device which allows you to turn the wrench to tighten or untighten without having to remove and readjust the position if the wrench handle hits an obstacle after each turn. It makes working in tight areas a lot easier.
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The foundation for any socket set, a socket wrench uses a ratcheting mechanism (similar to a ratcheting wrench) to allow you to quickly tighten or untighten nuts or bolts without lifting the wrench off the fastener. Available with 1/4″, 3/8″ (most common), 1/2″, and 1″ drives, you simply fit the correct size socket that you’ll need, on top of the drive. If the handle meets an obstacle while being turned, you can simply reverse course to give yourself room and then continue working.
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This socket wrench is designed to deliver a specific amount of torque without overtightening. This amount can be calibrated, and both manual and digital variations are available. It’s most commonly used for automotive work such as tightening wheel lug nuts but can also be used on bicycles, farming equipment, or any instance where tightening a nut or bolt to a specific torque specification which is usually set by the manufacturer.
Other Wrench Types
While you might have heard someone mention these specialty wrenches, chances are you’ve never owned one. They tend to be used for very specific tasks, or are simply no longer in common use outside of a few industries.
Once the big daddy of wrenches, the alligator wrench was named due to the way it gripped nuts. The top of the jaw is serrated, while the bottom is smooth, The handle looks more like a pointy fang than its modern cousin, the pipe wrench. As these were designed mainly to handle square-shaped heads, it has become rare to see them outside of movies.
This single-piece wrench has a C-shaped, serrated head and may include square slots and/or a hole to attach a ratchet handle. Used for gun repair and maintenance, they are available in a range of designs and are usually sized to fit specific types or models of gun.
This peculiar wrench has a long, T-shaped handle ending in a curved, serrated jaw. Its primary function is to loosen or tighten the fixtures under sinks and toilets, resulting in it also being known as a faucet wrench.
No, this isn’t something out of The Six Million Dollar Man. It’s a specialty wrench that has a round opening and two handles similar to those of pliers. When placed around the target head, the two handles can be squeezed, causing the hole to tighten and grip the head firmly, making this an adjustable box-ended wrench.
Available in a variety of styles, the drum bung wrench (also called a drum plug wrench) is a socket-style wrench. It was designed specifically to remove the plastic or metal bung (cap) on drums or barrels. Special “sparkless” versions are available when dealing with flammable materials.
Imagine an open-ended wrench after an elephant steps on it and you’ll have a cone wrench. These wide, flat wrenches are used on the cone portion of a cup and cone hub. It’s mostly used for bicycles or adjusting the leveling feet of washing machines, but sometimes employed on other gentle projects where a normal open-ended wrench is too thick.
Die Stock Holder Wrench
Available for both male and female-style dies, this two-handed wrench grips the die in the middle using a screws to secure it. These dies are used in creating the threads on nuts and bolts.
Dog Bone Wrench
Named after its bone-shaped appearance, this wrench is also sometimes referred to as a dumb-bell wrench. Each side of the two box-shaped ends has a different socket size. These are used almost exclusively for bike maintenance, although their ability to fit into small spaces has occasionally made them useful elsewhere. Some dog bone wrenches have swivel heads for even more flexibility.
A square-holed socket wrench, a drum key has a T-shape with flattened handles. As the name implies, it is used to tune various percussion instruments, such as drums. Drum keys with longer handles allow you to apply more torque than the shorter handles.
Fan Clutch Wrench
These flat spanners have a U-shaped opening at one end. They are designed specifically for removing fan clutches on cars. Some also have a squared opening at the other end, allowing them to double as a clutch holding tool while a second wrench is used to turn the hex nut.
Fire Hydrant Wrench
These large box-ended wrenches have a hexagonal shape that was designed solely for use on fire hydrants. As a result, a hydrant can only be opened using one of these tools. The end is typically adjustable and this wrench is known for its long handle to allow the user to apply more torque.
Flare Nut Wrench
Sometimes referred to as a line wrench, these are another hybrid of box and open ended designs, The opening is just wide enough to fit around a tube, but it still grips nuts like a box end. These wrenches are especially useful on softer metals prone to damage from open-ended wrenches, such as those used in plumbing.
Garbage Disposal Wrench
There are actually two different types of wrench used for clogged garbage disposals. Many models come with a large type of allen wrench which is used to dislodge clogs. For handling the large nuts, a second type of flat wrench with a squat, pivoting U-shaped head is used. This latter can also be used to dislodge clogs in the cutter heads, just like the allen variant.
This is the type of wrench referred to when speaking of sabotage (i.e. “throwing a wrench/spanner into the works”). It’s an older form of adjustable wrench similar to an alligator wrench, but with smooth jaws and rounded handle. Its association with sabotage heralds from its former role as a standard tool in most industrial branches.
Pedal wrenches have a rounded tip with generally one or two U-shaped recesses. As the name implies, the wrench is used for repairs involving pedals. Thus is it used most often in bicycle repair shops or for fairground rides such as pedal boats.
While the name might not seem familiar, you have likely used these at some point in your life. The flat-edged jaws are at an angle and each is attached to a handle, which are connected by a bolt. The bolt can slide between two or more positions of an opening on the upper jaw, allowing the wrench to be adjusted to fit different sizes of head. The name comes from the way this tool is gripped, which is the same as a pair of pliers.
Similar in design to pliers wrenches, the jaws are shaped to fit hexagonal nuts. The jaws are adjustable to fit a variety of pipe fittings. It is used exclusively in plumbing for work on pipes and fixtures.
Not to be confused with the British term, spanner wrenches are a highly specialized class of tools that have a curved end which may resemble either a hook or a C-shape. These have pins which allow them to be used on a variety of items, from spanner head screws to retainer rings.
Spark Plug Wrench
This double-ended hex socket requires a T-bar handle to use. As the name implies, it is designed to fit onto spark plugs and found anywhere that performs automotive, lawnmower, or other engine repairs and maintenance. Many sockets sets these days include a 1-2 spark plug sockets so check your sockets first before buying a standalone wrench.
These tiny wrenches are designed for maintaining the spokes on wire wheels. One end has a slot that fits around the spoke, while the other end has a drive head which fits around the nipple nut. Due to the size and shape, this wrench can be rotated in a full circle without having to remove it. The most common place to find this tool is a bike repair shop. Some variations more closely resemble a tiny open-ended wrench, while others look more like a piece of curved, flat metal.
Another tool which has fallen out of common use, this open-ended wrench had a spike on the opposing end which was used to line up the holes on pipes. It has since been made obsolete by the plumber’s wrench, although it can still be found in the occasional toolbox.
Most commonly seen in use for oil filter changing, these have a rubber, fabric, or metal band or chain that loops through a handle. This self-tightening tool works best on round objects that are too greasy or oily for a normal wrench to grip.
Referred to as a short body wrench in polite circles, this is a shorter version of a combination wrench, allowing it to fit into more confined spaces. Some newer versions also have a hinge along the handle to allow either end to be angled for even more precise use.
This key fits the square drive of taps, which are used in cutting female threads (such as those inside a nut). The shape of these wrenches may be either T-shaped or a double-handled bar with the attachment socket in the middle.
Another one of those wrenches you’ve seen but never heard of, a tension wrench is the “key” component in lockpicking and can be found in a wide range of designs. They can be rigid or flexible and are used to apply tension while the pick does its job. If you’ve ever seen someone picking a lock in a movie or video game and wondered why they only moved one of the two tools, the stationary one is the tension wrench.
Sometimes referred to as a star-headed key, this cousin of the allen wrench is designed to fit into the star-shaped heads of certain bolts and screws. While they can be purchased in the same L-shape as the average allen, you can also purchase these in a housed set that more closely resembles a swiss army knife than a wrench set.
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