Picture this scenario: one afternoon you’re cleaning your favorite piece, then the unthinkable happens: you’ve broken your downstem right in two. Now you need a replacement. We’ve got you covered there. There is only one issue, you don’t know what size you need. Never fear, I’m here to show you how to measure your joint size.

What are the Different Joint Sizes?

First, when we say "joint size" what are we referring to? We're not talking about a really large J, though that would be nice right now. When people talk about joint size they are referring to the size of the hole the downstem goes into. There are four industry standards when it comes to joint size: 10mm, 14.5mm, 18.8mm and 29.2mm. Of those four, the two most common are 14.5 and 18.8mm. Sometimes you might see sizes indicated as 14 and 18mm. When other shops do this, they really mean 14.5 and 18.8mm. Glad we could clear that up. 10mm and 29.2 are less common, but you should know about them of course!

How do I Figure Out My Joint Size?

The easiest way to figure out your bong’s joint size is to compare your bong’s joint to the size of a standard American dime. 18.8mm is just about the size of a standard dime. If your bong is smaller, then it’s either 10mm or 14.5mm. If it’s larger than the dime, then your bong’s joint size is 29.2.

So what do you do if your bong’s joint size is smaller than 18.8mm? Try next measuring with your pinky finger. If your pinky snugly fits into the joint, then you’ve got a 14.5mm. If smaller, then you’ve got a 10mm piece. Easy enough right?

One thing that you would do well to keep in mind is that not everyone’s pinky is a uniform size; if you’re a person with large hands, your pinky might be a bit larger than 14.5. This is why you should start with the dime!

Another thing that people do not consider at times is whether or not the original downstem that came with your bong is tapered, that is whether one end is 18.8 and the other is 14.5mm. This is why it is a good idea to look at the size of your slide bowl as well. You can figure out the size you need by using the same methods described above.

Once you have mastered this, you know how to match any bowl and downstem to your piece! Now, you’re ready to shop for a replacement!

Image Source: Instagram/grasscityheadshop

Got any other tips for measuring joint size? Tell us in the comments!