A Complete Guide to Spark Plug Socket Size

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If you’ve ever tried to learn anything about cars before, chances are you’ve heard of spark plugs. Spark plugs are basically small cylinder-shaped objects that screw into your engine. Once in, they provide the necessary spark that ignites the fuel and propels the car forward. 

Although they are little and inexpensive, they perform a vital function, and have to be checked and maintained regularly. When a spark plug fails, it affects the whole engine. You can have anything from a misfire to an engine that just won’t run.

The good news is that replacing spark plugs is almost always a cheap and easy process. While there are some exceptions, most spark plugs are easy to get to, and replacing them is simply a matter of unscrewing the plug and putting in a new one. Of course, the right tool for the job is crucial, and this is where spark plug sockets come into play. 

Read on to learn more about spark plug sockets, including:

What is a Spark Plug Socket?

MR CARTOOL Spark Plug Socket 2PCS Spark Plug Socket Set Compatible with BMW Spark Plug Socket Kit 360° Adjustable 14mm Spark Plug Socket Magnetic with Magnet

A spark plug socket is basically a variation on a standard socket wrench. Like a regular socket wrench, spark plug sockets come in different interchangeable sizes that can be attached to a wrench handle for maximum torque. The difference, however, is that spark plugs have delicate tips that need to be protected. Because of this, spark plug sockets usually contain a rubber tip inside the socket. This tip helps to protect the more vital parts of the spark plug, making sure they don’t get scratched or bent.

In some cases, spark plug sockets will instead be equipped with a magnet. This magnet helps keep the spark plug in place inside the socket. This helps it not accidentally fall out and hit the ground, which can be damaging to the plug. 

Spark Plug Socket Buying Guide

If you want to know everything you need to know about getting and using the right spark plug socket, keep reading.

Spark Plug Socket Sizes and their Uses

Many people think that all spark plugs are the same size. The truth, however, is very different. Depending on the vehicle there are several different sizes, and knowing the size is important to getting the right spark plug socket.

While there are many different possible sizes of spark plugs, in most cases a spark plug will be either 5/8” or 13/16”. The 5/8″ covers most newer vehicles, including makes like Nisssan, Chevy and Subaru, as well as most small engines that you might encounter in lawnmowers and the like. 13/16” spark plugs are also common, and are most often found in older vehicles. 

There are, however, other sizes used for more specialized engines. These include 14mm plugs which can be found in newer European and Asian vehicles, 9/16”, which can be found in some Ford models, 18mm, a common size for motorcycles, 3/4″, another small engine size, and 7/8″, which you might find in tractors and some older vehicles.

What to Consider When Buying A Spark Plug Socket

If you are going to change the spark plugs yourself, then you need to know what to look for when buying spark plug sockets. There are kits available that include almost all spark plug sizes, and springing for one of these kits right away will save you the hassle of picking the right one. However, if you want to save some money, then you need to keep the following in mind.

Type of Engine

First, what type of engine are you working on? As you can see above, this goes a long way towards determining the size of the plug. Most cars will fall into either the 5/8″ or 13/16” size, while small engines might be one of the other sizes. Your best bet is to do your research in advance by checking your vehicle’s manual or going on Google.

Standard vs. Deep

Second, take a look at the spark plug and how it sits in the engine. Is it right on top, and easily accessible? Or is it recessed a little? Plugs that are recessed might need a deep socket to reach. This is nothing more than a longer spark plug socket, which lets you get more of those hard-to-reach spark plugs.

Wall Thickness

A third factor to consider is the room around the spark plug itself. Some plugs are sitting pretty snug, and there’s very little room around the plug to fit a socket. A thin-walled socket needs to be used in this case. Just like sizes, sockets come in different thicknesses as well to help make sure you can get to the plug with minimal problem.

Do I Need a Spark Plug Socket Wrench?

You might be wondering if this is all really necessary. After all, you can just a standard socket wrench, right? 

The short answer is yes, you can. However, without the modifications found on the standard spark plug sockets, you run the risk of damaging or dropping the plug, which just makes your repair take longer and cost more. As always, it’s important to have “the right tool for the right job,” and spark plug maintenance is no expectation!

In Conclusion

We hope that this guide has helped you learn what you need to know about spark plug sockets and spark plug maintenance.

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