Are spanner wrenches universal

Are Spanner Wrenches Universal?

After realizing that I needed to use a spanner wrench for something I was trying to do around the house recently, I began shopping online for one as usual. However, I wasn’t sure what size I needed, and if all of these tools were the same. So, I did some reading to find out if spanner wrenches are universal.

Are spanner wrenches universal? While all spanner wrenches are not exactly the same size and shape, each of these wrenches will be able to fit up to 3 metric and 3 non-metric sizes.

Spanner wrenches are small tools that are most commonly used to apply torque while turning or fastening objects. While different in size from the traditional wrench, there are several variations of spanner wrenches that are ideal for individual circumstances.

If you had the same question that I did when I found myself in this situation, keep reading to find out everything you need to know about spanner wrenches.

Are Spanner Wrenches Universal?

While there is such thing as a universal spanner wrench, which will be described more in detail later, each spanner wrench is not exactly the same, nor are they all interchangeable with each other.

To be more specific, there are approximately 18 different standard sizes for a spanner wrench. You might be surprised to learn the information that is provided in the list of spanner sizes below.

Spanner Wrench Standard Sizes:

  • MQ.6 or 5/32” (3.2mm)
  • M2 or 3/16” (4mm)
  • M2.5 or 1/4” (5mm)
  • M3 or 5/16” (5mm)
  • M3.5 or 11/32” (6mm)
  • M4 or 3/8” (7mm)
  • M5 or 7/16” (8mm)
  • M6 or 1/2” (10mm)
  • M7 or 9/16” (11mm)
  • M8 or 11/16” (13mm)
  • M10 or 5/8” (17mm)
  • M12 or 3/4” (19 mm)
  • M14 or 7/8” (22 mm)
  • M16 or 13/16” (24 mm)
  • M18 or 15/16” (27 mm)
  • M20 or 1 1/8” (30mm)
  • M22 or 1 5/16” (32 mm)
  • M24 or 1 5/16” (36mm)

As you can see, the standard sizes for a spanner wrench can range anywhere from just over 3 millimeters to almost 40 millimeters.

While all of the spanner wrenches that were mentioned in the list above come in a variety of sizes, each size is sometimes used for a special purpose. To get a general idea of what kinds of tasks these spanner wrenches can specifically be used for, take a look at this short list of examples.

Spanner Wrenches for Specific Purposes:

  • M6 or 1/2” (10mm) Spanner Wrench – used for Dome Nut
  • M8 or 11/16” (13mm) Spanner Wrench – used for Full Nut
  • M10 or 5/8” (17mm) Spanner Wrench – used for Bolt & Nyloc Nut
  • M14 or 7/8” (22 mm) Spanner Wrench – used for Nut
  • M16 or 13/16” (24 mm) – used for Bolt

To conclude the debate on whether or not all spanner wrenches are universal, or created in the same size and shape, there is a huge span of standard-sized spanner wrenches that are available on the market.

In addition to the wide range of sizes, some of these wrenches are ideal for certain purposes, such as securing a Dome Nut into place. With that being said, there is no way that just one of these traditional spanner wrenches can be used for all of these purposes at the same time.

Universal and Adjustable Spanner Wrenches

While it is true that the traditionally shaped spanner wrench is not necessarily universal for every task you can think of, there are special spanner wrenches that can be interchangeable for any purpose.

This can be achieved by using something called an adjustable spanner, which can morph into several different sizes to complete tasks with just one tool.

There are also tools, known as Universal Spanner Wrenches, that take an entirely different shape than their more common counterparts.

The rest of this section will identify the characteristics of both a universal spanner wrench, as well as an adjustable spanner wrench, as well as how they are typically used.

Universal Spanner Wrench:

  • Interchangeable with any spanner wrench
  • Can be used for almost any task involving a spanner
  • Can conform to any size needed

Universal spanner wrenches, as mentioned before, have a rather unconventional shape. Unlike the traditional spanner wrench with a handle and one opening, the universal spanner wrench looks more like an all-in-one tool.

To be more specific, the universal spanner wrench does not have a specific handle area with an opening at the end. Depending on the manufacturer, the average universal spanner will have a few openings along the bottom side of a curved piece of metal.

Usually quite large, these tools can be rotated around to fit different sizes during the same project, without having to manually adjust anything.

Adjustable Spanner Wrench:

  • The size of the opening is adjustable
  • Moveable jaw for ease of use
  • Can conform to almost any size needed

In order to use an adjustable spanner wrench, you will first need to identify the object you would like to fasten. This object could be a nut or a bolt, but is not limited to these two options.

Next, you will open the adjustable section of the wrench by turning the screw that is connected to this area in a counter-clockwise direction. You might need to use another tool to get this open, but you could also just use your fingers and some additional force.

To ensure that you will be adjusting the opening to exactly the right size, you will need to place the open jaw over the nut. Holding it very still, secured around the nut at this point, you will turn the wrench again to tighten it. This time, it will be rotated in a clockwise direction to secure the position.

Now that your adjustable spanner wrench has been properly fitted to the nut or bolt in question and properly secured, you will be able to use it for this task as you normally would.

The great thing about adjustable spanner wrenches is the fact that they can always be adjusted to the exact size that you need them to be, and the process is as easy as opening and closing it relatively quickly.

What Is The Difference Between a Spanner Wrench and a Wrench?

With all of the mentions of spanner wrenches throughout this article, you might be wondering how these types of tools relate to actual wrenches. After all, “wrench” is in the name.

These quick outlines will give you an idea of the differences between a spanner wrench and a regular one.

Spanner Wrench:

  • One opening on the side
  • Shaped like a single claw
  • Teeth in the opening
  • Adjustable to different sizes


  • One opening in the middle
  • Shaped like a pair of claws
  • No teeth in the opening
  • Sometimes adjustable to different sizes

While these two tools do have a lot of similarities, including the standard handle, opening, and their ability to loosen and fasten objects, they are quite fundamentally different from each other.

More specifically, the spanner wrench only has one opening on the side, similar to a claw, while the traditional wrench has its opening in the middle, more like a set of crab claws.

Spanner wrenches might have teeth in the opening, while most wrenches have a smooth surface within this area. Additionally, wrenches are only adjustable on occasion, while it is more common to find an adjustable spanner wrench.

In conclusion, the spanner wrench is very different in shape and features than the traditional wrench. Although the average spanner is not universal, there are some other ways to achieve the versatility that you desire with the same kind of tool.

This can be done with the use of an adjustable spanner wrench that can switch to different sizes, or a universal spanner wrench that will be fit for almost any task you will ever need.

Regardless of what type of spanner wrench you choose to purchase and use on your next project, you can certainly use a few of the shortcuts that were outlined in this article in order to make sure that you never run into the same problem as I did!

Related Questions

How can I figure out what the size of my spanner wrench is?

In order to measure a spanner wrench, you will need to find out what the length of the shaft is. With so many sizes from 4 to 18 inches in length, spanner wrenches are differentiated from each other using this method. The size of the wrench will be reflected in the size of the handle. Otherwise, the size could be printed on the handle.

What are the different types of spanners?

Spanners come in multiple different varieties, including the traditional open-ended model that was described in earlier sections. Some of these varieties include the ring spanner, which holds nuts through a ring, as well as the combination spanner that has a ring on one end, while the opposite end is completely open.