Ask The Editors: Screw Top Spark Plug Question

Let’s get to know the three types of spark plug terminal offered.

While everyone has some idea of the layout and design of a spark plug, the individual labeling can be elusive. The area you are referring to is called the terminal and being able to screw off the tip is known as a removable terminal nut.

Here’s the good news, all three of the terminal configurations ever offered are certainly still available from every plug manufacturer. What are the three? Solid – which, as the name suggests, has a terminal nut permanently fastened to the thread. Threaded stud – which again, like it sounds, is the skinnier threaded tip (and the type your machine must need) and Removable – the most common option because it provides both types in one package. Leave the terminal nut on if needed or screw it off it you need the threaded stud.

As for NGK – it sounds like you must have found a rare BP5ES in Solid configuration. Go online and search for the NGK BP5ES 6511 model, which is Removable configuration. You should be able to grab one for under $3.

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