Every water pipe, bong, and dab rig comes in one of three joint sizes: 10mm, 14mm, and 18mm. Each of these joint sizes comes in one of two forms, male or female, indicating whether the joint protrudes outward or caves inwards. While most glass pieces come standard with a bowl, you need to know your piece’s joint size when picking a replacement bowl. Taking both joint size and “gender” into account there are a total of six joint possibilities. We’re going to clear up any confusion and break down each joint type:
What is a Joint?
Before we get into the gritty details, let’s talk about what a joint is. To get the most out of a water pipe (or any glass pipe for that matter), air control is essential. A joint is an opening at the end of a bong or water pipe that acts as a receiving end. Inhaling from the mouthpiece of the pipe pushes whatever is at the other end through the piece. Hence, a joint is used as the entrance point for smoke. It holds a glass or ceramic bowl or nail/banger. Tobacco herb or legal concentrate is lit in the bowl while the user inhales. To get the smoke out of the piece, the user removes the bowl from the joint. This allows fresh air to flow through the pipe and push out smoke. You may have heard of this referred to as “clearing.”
What most people take for granted is the fact that joints are often made with reinforced glass. The glass is either coated with an extra, scratch resistant material or matted. This prevents scratching and puts a barrier between the hot bowl or nail and the glass piece. Extra thick borosilicate glass is usually used as the buffer between the bowl and piece.
Glass joints either feed into a downstem or a sidearm. Sidearms are positioned at 45° or 90° depending on the type of accessories the pipe is meant to bear. Downstems can be diffused and sometimes serves as the first percolator diffusion system in the water pipe.
You could use your imagination to get the idea of where the terms “male” and “female” come from when we talk about joints. A male joint protrudes from a water pipe’s downstem or sidearm. It accepts “female” bowls which go over the male joint. Most accessories are female, due to their size. They need stable platforms and larger surface areas to remain secure. Almost all dab rigs use male joints. Dabbers do not want their extremely hot nails or bangers accidentally falling off their joints.
Female joints are more common in bongs. They are openings that accept male joints. A male attachment is very easy to remove from a female joint. The large opening of a female joint makes cleaning excess tar or ash from a bong very easy.
10mm Joint Size
The 10mm joint size is used for smaller, transportable pieces. Many mini or nano rigs and bongs use 10mm joints. These joints are meant for smaller bowls and nails. Here is an example of a mini dab rig that uses a 10mm joint:
14mm Joint Size
The 14mm joint size can handle larger, decorated bowls and some accessories. This is the most common joint size found in water pipes.
18mm Joint Size
18mm joints are the largest of the three joint sizes. These joints can easily support big loads. Bongs and dab rigs that are meant to support large accessories like ash catchers use 18mm joints.
29mm Joint Size
These joint sizes are rarely used, but do exist in some pieces that use large accessories or diffused downstems. The large opening in these joints makes large percolation units easy to input, but also requires a larger base and more support.
Adapters are used to connect one joint size to another sized bowl. For example a 14mm/18mm male to female joint fits into a 14mm male joint and converts the joint into an 18mm female joint. This is ideal for those who would like to connect mismatched bongs and bowls or accessories.