Pipe Wrench Vs Monkey Wrench: What’s the Difference?

Both a pipe wrench and a monkey wrench look pretty similar, if not identical, to an untrained eye. In all honesty, there are more than enough reasons to jumble between the two.

Both the tools are made in a similar fashion; both are big and usually bulky, both are heavy, and they function similarly. Despite all the similarities, The two are quite different. Let me explain how.

What is Pipe Wrench?

A pipe wrench is any of several types of wrenches that are designed to turn threaded pipe and pipe fittings for assembly (tightening) or disassembly (loosening). The Stillson wrench, or Stillson-pattern wrench, is the usual form of a pipe wrench, especially in North America.

The Stillson name is that of the original patent holder, who licensed the design to a number of manufacturers. The patent expired decades ago. Another type of wrench often used on pipes, the plumber wrench, is also called a pipe wrench in some places.

The Stillson wrench is an adjustable wrench (spanner) with hardened serrated teeth on its jaws. The hard teeth bite into the softer metal of the round pipe and provide the grip needed to turn a pipe, even against fair resistance.

The design of the adjustable jaw, which permits a certain amount of intentional play out of square, allows it to bind on the pipe, with forward pressure on the handle pulling the jaws tighter. Two leaf springs, above and below the knurled adjusting knob, help unlock the jaw when pressure on the handle of the wrench is released.

Pipe wrenches are not intended for regular use on hex nuts or other fittings. However, if a hex nut becomes rounded (stripped) so that it cannot be moved by standard wrenches, a pipe wrench can be used to free the bolt or nut, because the pipe wrench is designed to bite into rounded metal surfaces.

Pipe wrenches are classified by the length of the handle. They are generally available in sizes from 6 inches (150 mm) to 48 inches (1,200 mm) or larger. They are usually made of cast steel. Today, aluminum might be used to construct the body of the wrench, although the teeth and jaw remain steel.

Teeth and jaw kits (which also contain adjustment rings and springs) can be bought to repair broken wrenches because that can be cheaper than buying a new one. Repairing a high-quality wrench can be more economical (taking into account the total cost of ownership) than either buying a new high-quality wrench or buying cheap wrenches repeatedly.

Best For

As the name suggests, pipe wrenches are best for rounded surfaces like threaded pipe or pipe fitting. The jaw’s teeth allow the wrench to adequately grip rounded surfaces. Without these teeth, the wrench would not be able to grip the rounded surface enough to twist it. That is why the monkey wrench is only suitable for flat surfaces; it cannot grip round surfaces correctly.

How to Use?

You will use the pipe wrench just as you would use the monkey wrench. Place the jaws around the pipe and adjust the upper jaw so that both jaws fit tightly around the pipe or rounded surface. Turn the wrench clockwise to tighten the pipe or turn it counterclockwise to loosen it. Remove the wrench from the pipe by unscrewing the screwing mechanism.

What is Monkey Wrench?

The monkey wrench is a type of adjustable wrench, a 19th-century American refinement of 18th-century English coach wrenches. It was widely used in the 19th and early 20th centuries. It is of interest as an antique among tool collectors and is still occasionally used in maintenance and repair when it happens to be convenient.

The term monkey wrench is also sometimes used loosely, usually by non-tradespeople, to refer to the pipe wrench (owing to their broadly similar shapes). A wrench with smooth jaws is not used for turning threaded pipe. The largely US idiom “to throw a monkey wrench into…” means to sabotage something.

These are also known as a Ford wrench owing to this type of wrench being included in the tool kit supplied with every Ford Model A. They are still used by aircraft technicians, mainly when large but low torque fasteners are involved.


Many people mistake the monkey wrench for a pipe wrench due to their similar overall shapes. The monkey wrench uses a flat piece of iron and is 24 inches long. It has an L or F-shaped appearance with a fixed upper jaw and a movable lower jaw. The body is relatively bulky for a hand tool.

The lower jaw moves up and down through the wrenches screw mechanism. The lower jaw movement mimics a monkey climbing up a branch, which is where the wrench gets its name.

A monkey wrench is different than a pipe wrench, however, based on the jaw design. Monkey wrenches have smooth jaws or jaws with no teeth. This means that monkey jaws have a smooth jaw that is ideal for turning or twisting flat surfaces.

Best For

The flat jaw on the monkey wrench makes the tool most suitable for fasteners with flat surfaces. Since they don’t have teeth, monkey wrenches are not ideal for rounded surfaces. Instead, monkey wrenches are best for clamping fasteners such as lug nuts, bolts, and screws because of the flat jaws.

How to Use?

Attach the jaw of the monkey wrench to the fastener head. You will then slide the lower jaw to fit the specific fastener. Make it so that both jaws of the monkey wrench grip firmly onto the flat sides of the fastener. To tighten the fastener, turn the monkey wrench clockwise.

In contrast, turn the monkey wrench counterclockwise to loosen the fastener. Whenever you are done, unscrew the screwing mechanism so you can safely remove the wrench from the fitted surface.

How to Know When You Need a Monkey Wrench or Pipe Wrench?

Although monkey wrenches and pipe wrenches are often confused, it is pretty easy to know when to use which one after you learn about their differences. In short, you will select the wrench based on the surface that you need to adjust.

Monkey wrenches and pipe wrenches are very similar, but they have different jaw designs.

If you need to tighten or loosen a fastener with a flat surface, you will always choose a monkey wrench. On the other hand, select a pipe wrench if you need to tighten or loosen a pipe or other rounded surface. It really is as simple as that.

ScenarioWhich Pipe to Choose
Nuts, bolts, or other fasteners with flat surfacesMonkeywrench
Pipes, pipe fittings, or other rounded surfacesPipe wrench

Since each wrench satisfies a different need, it’s always nice to have both wrenches on hand since they are useful. If you’re able, keep both wrenches in your kit and pull each one out for individual projects. Doing so will ensure that you are prepared no matter what.

Factors to Consider When Buying a Wrench

Although monkey wrenches and pipe wrenches are not used interchangeably, you should still consider the same factors when buying them. Below are key factors to consider when buying a wrench to ensure you get the most bang for your buck.

1. Durability.

When selecting any tool, you need to consider durability. Always opt for a wrench that is made from heavy-duty materials such as aluminum or steel. These materials ensure that your wrench will last a long time, even after frequent use. Read reviews and buyer’s guides on individual wrenches before spending any money.

2. Size and Weight.

Pipes and fasteners come in all shapes and sizes. Ensure that the wrench you choose fits the fasteners and pipes you intend to be working with. Pipe wrenches come in many sizes to make sure that all pipe diameters can be fitted properly.

Directly related to size is weight. Heavy-duty wrenches will weigh more because they use more dense materials. Although you do not want to sacrifice any durability for weight, it is always a good idea to look for lighter tools simply because they will be more comfortable to use, especially for extended times.

3. Grip

To use your wrench for a long time, you should look for options with comfortable grips. Rubber is often used as the gripping material. These grips ensure that your hand stays comfortable no matter how long you use the tool. Not all wrenches come with a grip.

4. Jaw Type

As we saw by looking at the monkey and pipe wrench, you need to select a jaw type based on the surface of the fitting you intend to be working on. Rounded surfaces, such as a pipe, require jaws that have teeth. The teeth allow the wrench to better grip on to the pipe to be loosened or tightened. In contrast, select a flat jaw for flat fasteners since it will provide a snug fit.


Monkey wrenches and pipe wrenches are very similar, but they have different jaw designs. Monkey wrenches have flat jaws, while the jaws on pipe wrenches have teeth for gripping rounded surfaces. You should use monkey wrenches for flat surfaces and pipe wrenches for rounded surfaces.

It is always recommended to have various wrenches in your set since you never know what projects may get thrown your way. We advise adding both a pipe wrench and an adjustable wrench to your kit to help you be the most prepared. The reason we say get an adjustable wrench, as opposed to a monkey wrench, is that adjustable wrenches have a more ergonomic and modern design.