Glass Grinding Sizes Guide
Here is where we will explain some of the most common glass ground joint sizes and their applications. Some of the common accessories that you will encounter and need to know about their compatibility are stems, bowls/cones, keck clips, titanium nails, quartz nails and ceramic nails.
Female are the most common style of glass joints that you will see, this is the joint that most bongs and downstems will have where they accept the add on accessories. They are easily identifiable due to the fact that they allow a male glass joint to fit inside of the joint. As an example a standard cone/bowl with a male joint will fit in to the female.
Male glass joints are growing in popularity and these are the glass joints that you will usually see on a dedicated concentrate rig. The male joint is also the most common accessory joint, meaning that most cones/bowls are a male joint that will fit in to the female joint found on almost all bongs.
The image is showing the difference between a male glass joint cone piece on the left and a female glass joint cone on the right. Male glass cones are by far the most common gender when purchasing a new cone piece.
How to measure Glass Ground Joints
Female Ground Joints:
Measure the "inside" diameter of the top of the female joint. There may be some slight variations between each brand of joint, although the measurement closest to 10mm, 14.5mm, 18.8mm or 29.2mm will be the correct size of the joint.
Male Ground Joints:
Measure the "outside" diameter of the widest part of the joint. There may be some slight variations between each brand of joint, although the measurement closest to 10mm, 14.5mm, 18.8mm or 29.2mm will be the correct size of the joint.
10 mm Glass Joint
10 mm glass grindings are usually found on concentrate rigs and unique glass pieces. You will usually find 10 mm as Male glass joints. These are sometimes also called Nano or micro joints.
14 mm Glass Joint
The 14.5 mm glass joints are also sometimes referred to as sg14 sizing. One of most popular sizes that you will find on any bong, water pipe or dab rig.
14mm / 14.5mm / SG14 are all the same size.
18 mm Glass Joint
One of most popular sizes that you will find on any bong, and can sometimes be called either a sg18 or sg18 ground joint. Even though it is an extremely popular size a lot of water pipes will use a reducer downstem which converts the 18.8mm joint to a 14.5mm joint.
18mm / 18.8mm / SG18 are all the same size.
Image showing a side by side comparison of the 14mm male and 18mm male EHLE glass cone pieces.
29 mm Glass Joint
Sometimes referred to as a sg29 glass joint the 29.2mm is not nearly as common, due to its increased hole size it allows the use of more unique diffuser downstems. Some of those include a six arm downstem, shower head, triple disc and many more. Allowing you to be able to create an even more diffused smoke resulting in a more enjoyable experience.
There you have it a simple to follow guide on explaining the most common sizes that are used within the industry. We hope this has helped you on your quest to find answers.