Wrenches and spanners are two of the most common tools in any mechanic’s toolbox. Both of these tools serve very similar purposes, but some key differences between them are important to understand if you want to use them effectively.
In this article, we’ll take a closer look at the differences between wrenches and spanners and help you understand which tool is best for different types of jobs.
What is a Wrench?

A wrench is a type of hand tool that is used to apply torque to a bolt or nut. The most common type of wrench is the adjustable wrench, which has a sliding jaw that can be adjusted to fit bolts and nuts of different sizes.
Wrenches come in many different shapes and sizes, and they can be made from a variety of materials such as steel, aluminum, or titanium. Some wrenches are designed to be used with specific types of fasteners, while others are more versatile and can be used with a wider range of nuts and bolts.
What is a Spanner?

A spanner is also a hand tool that is used to tighten or loosen bolts and nuts. However, unlike a wrench, a spanner has a fixed size and shape, which means that it can only be used with nuts and bolts of a specific size.
Spanners are typically made from steel or chrome-vanadium alloy, which gives them strength and durability. They are available in many different sizes and shapes, including open-end spanners, ring spanners, and combination spanners.
Wrench vs Spanner Difference
Now that we have a basic understanding of what wrenches and spanners are, let’s take a closer look at the main differences between these two tools.
Adjustable vs. Fixed Size
One of the biggest differences between wrenches and spanners is that wrenches are adjustable, while spanners have a fixed size. This means that a wrench can be used with bolts and nuts of different sizes, while a spanner can only be used with nuts and bolts that match its specific size.
For example, if you have an adjustable wrench, you can use it to tighten or loosen a nut or bolt that is slightly larger or smaller than the size of the wrench. However, if you have a 10mm spanner, you can only use it with nuts and bolts that are exactly 10mm in size.
Shape
Another key difference between wrenches and spanners is their shape. Wrenches typically have a straight handle, while spanners have a curved or angled handle.
This shape difference can make a big difference when working in tight spaces. Wrenches with a straight handle are often easier to use in tight spaces where there isn’t much room to maneuver. On the other hand, spanners with a curved or angled handles can be more comfortable to use for extended periods because they allow you to grip the tool in a more natural position.
Versatility
Because wrenches are adjustable, they are generally more versatile than spanners. A single adjustable wrench can be used to tighten or loosen a wide range of nuts and bolts, while a set of spanners will be required to cover the same range of sizes.
However, this versatility comes at a cost. Adjustable wrenches are often less precise than spanners because the sliding jaw can slip or shift during use. This can result in stripped nuts or bolts if too much force is applied.
Strength
Spanners are typically stronger than wrenches because they don’t have any movable parts. This makes them ideal for jobs that require a lot of torque or that involve stuck or rusted bolts.
Wrenches, on the other hand, are generally not as strong as spanners because they have a movable jaw that can flex or bend under heavy loads. For this reason, wrenches are better suited for jobs that require less torque or that involve bolts and nuts that are in good condition.
Which Tool is Right for You?
Now that we’ve explored the main differences between wrenches and spanners, how do you know which tool is right for your job? Here are a few basic guidelines to help you choose:
- If you need a tool that can be used with a wide range of nut and bolt sizes, an adjustable wrench is probably your best bet.
- If you need a tool that is stronger and more precise, a fixed-size spanner is a way to go.
- If you’re working in a tight space, a wrench with a straight handle may be easier to use, while a spanner with a curved handle may be more comfortable.
- If you’re working with particularly stubborn nuts or bolts, a spanner is likely to be a better choice because it’s less likely to slip or strip the fastener.
Conclusion
Wrenches and spanners both have their strengths and weaknesses, and the right tool for your job will depend on a variety of factors. By understanding the main differences between these two tools

Martin A. Sims is a technician at a reputed automobile service center for the last 5 years. After studying at San Mateo College of Silicon Valley on vehicle engineering, he has started his career at age of 24. now he is spreading his knowledge among beginners around the world through thewrenches.com.