Stems
Shop Bong Stems from Billy Mate, including removable glass downstems, slider stems and traditional Australian metal bonza stems in a range of sizes and fittings. Find replacement stems for compatible glass, acrylic, silicone and ceramic water pipes, with diffused and standard options available.
1: Bong Stems & Downstems by Billy Mate
A bong stem creates the airflow connection between the cone piece and the main water chamber of a compatible bong or water pipe.
Depending on the bong design, this may be a removable glass downstem, a glass slider-style stem, an Australian metal bonza stem or a stem that is permanently built into the bong.
Billy Mate offers replacement bong stems in different:
- Materials
- Lengths
- Joint sizes
- Connection systems
- Diffusion styles
- Designs
Choosing the correct stem is important because the length, diameter, joint size and connection type must match the bong.
A stem that is too long may sit incorrectly inside the chamber, while one that is too short may not reach the intended water level.
For glass systems, the joint sizes at both ends also need to be compatible.
The stem forms part of the bong's main airflow path.
A simple bong setup may look like:
Cone Piece → Stem → Water Chamber → Mouthpiece
When the bong is used, airflow travels through the cone piece and stem before entering the water chamber.
Different bong designs accomplish this in different ways.
Some use:
- Removable glass downstems
- Metal bonza stems
- Glass slider stems
- Built-in glass stems
- Stemless construction
The replacement part you need depends on the construction of your particular bong.
A glass downstem is a removable glass tube that fits into the joint of a compatible bong.
The lower section extends into the water chamber while the upper joint accepts a cone piece or another compatible accessory.
Glass downstems are common on modern glass-on-glass bongs and can be found on:
- Beaker bongs
- Straight bongs
- Gripper bongs
- Percolator bongs
- Bubble bongs
- Some silicone bongs
- Other glass water pipes
Because they are removable, glass downstems can generally be cleaned or replaced separately from the main bong.
The Australian metal bonza stem is a classic component used across many traditional Australian-style water pipes.
Instead of using a ground glass joint, the stem typically passes through the bong body using a flexible rubber or silicone grommet.
A traditional setup may look like:
Bong Body → Grommet → Metal Bonza Stem → Brass Bucket Cone
Metal bonza stems are commonly found on:
- Acrylic bongs
- Traditional glass bongs
- Bubble bongs
- Rubber base bongs
- Some silicone water pipes
Replacement bonza stems are available in different lengths, so measuring the existing stem or checking the original product specifications is important.
Glass stems and metal bonza stems perform a similar basic role, but their connection systems are very different.
Glass Stem
Common characteristics include:
- Glass-on-glass connection
- Ground glass joint
- Removable downstem options
- Different joint sizes
- Different diffusion styles
- Usually paired with a glass cone piece
Metal Bonza Stem
Common characteristics include:
- Metal construction
- Grommet connection
- Traditional Australian design
- Usually paired with a brass bucket cone
- Available in different physical lengths
A bonza stem cannot simply be replaced with a glass downstem unless the bong itself is designed for that different connection system.
Match the stem to the bong, not just the approximate size.
Glass downstems are commonly identified using two measurements.
You may see sizes such as:
18/14mm
This commonly means:
- The outside of the downstem fits an approximately 18mm bong joint
- The top of the downstem accepts an approximately 14mm cone piece
So the setup becomes:
18mm Bong Joint → 18/14mm Downstem → 14mm Cone Piece
19/14mm
This refers to a larger outer connection with a smaller inner cone connection.
Depending on manufacturer terminology, approximately 18.8mm joints may also be described as 19mm.
Other bong systems may use:
- 10mm
- 14mm
- 18mm
- 19mm
Always check both ends of the downstem before purchasing a replacement.
Stem length is just as important as joint size.
Two stems may use the same joint size but have completely different lengths.
A replacement stem needs to extend far enough into the water chamber without:
- Touching the bottom of the bong
- Sitting too high above the water
- Interfering with internal glass
- Preventing the stem from seating correctly
Stem lengths may include measurements such as:
- 5cm
- 8cm
- 10cm
- 11cm
- 14cm
- 17cm
and other lengths depending on the product.
The individual listing should clearly show how Billy Mate measures the stem so customers can compare it correctly with their existing component.
Before ordering a replacement, first identify which stem system your bong uses.
For a glass downstem, check:
1. Outer Joint Size
This is the section that fits into the bong.
2. Inner Joint Size
This is the opening that accepts the cone piece.
3. Stem Length
Compare the replacement with the original stem or the bong specifications.
4. Diffusion Style
Determine whether the original stem uses:
- Open end
- Slits
- Multiple holes
- Another diffuser design
For an Australian bonza stem, check:
1. Overall Stem Length
2. Diameter / Grommet Fit
3. Cone Connection
4. Existing Bong Opening
If you still have the original stem, using it as the reference is normally the easiest way to identify the correct replacement.
Not all glass downstems release airflow into the water in the same way.
Standard / Open-End Downstem
A standard stem uses an open end where airflow exits into the chamber.
This is one of the simplest downstem constructions.
Slit Diffused Downstem
A slit diffused downstem contains multiple slits near the lower end.
Instead of air exiting through one opening, it is divided across several smaller openings.
Multi-Hole Diffused Downstem
These use several small holes around the lower stem.
The holes divide airflow into multiple streams as it enters the water.
Matrix or Specialty Diffusion
Some more advanced stems incorporate specialised glass diffusion patterns.
The exact design should be listed on the individual product page.
A diffuser changes how airflow exits the bottom of the stem.
A simple open-ended stem releases airflow through one main opening.
A diffused stem divides that airflow through multiple slits or holes.
This creates:
- More individual bubbles
- Greater interaction with the water
- A different airflow pattern
- A different bubbling sound and feel
The number, size and arrangement of openings can vary considerably between downstem designs.
Customers who want a replacement similar to their original setup should select the same or a compatible diffusion style.
Some bong designs use a glass slider-style stem rather than a conventional two-piece glass downstem and cone setup.
The exact design can vary, but slider systems generally involve a removable glass component that fits directly into the bong's connection.
Because slider stems can differ between manufacturers, check:
- Diameter
- Length
- Cone configuration
- Bong opening
- Grommet or glass connection
before purchasing a replacement.
Slider stems should remain a separate stem type in the Billy Mate filtering system rather than being mixed together with standard removable downstems.
Some bongs have a built-in glass stem.
In these designs, the airflow pathway is permanently incorporated into the bong rather than using a completely removable downstem.
Built-in stems are often found in:
- Dab rigs
- Bubblers
- Recycler pieces
- Compact glass designs
- Some advanced bong constructions
A built-in stem normally cannot be replaced in the same way as a removable downstem.
This is why Billy Mate product specifications should clearly distinguish between:
Removable Glass Downstem
and
Built-In Glass Stem
A stemless bong does not use a traditional removable downstem.
Instead, the airflow pathway is built directly into the glass structure of the bong.
Stemless construction may connect the joint directly to:
- The main chamber
- An inline perc
- A built-in diffuser
- Another internal glass section
If your bong is stemless, a replacement downstem is generally not required.
This is another reason customers should identify their bong's construction before purchasing replacement parts.
Billy Mate stems can use different materials depending on the bong design.
Glass
Common on modern glass-on-glass bongs.
Glass stems can offer standard or diffused designs and are available in different joint combinations.
Metal
Used extensively in Australian bonza-style bongs.
These stems generally use a grommet connection and brass cone piece.
Silicone
Some specialised or flexible water pipes may use silicone stem components.
The material alone does not determine compatibility, so always check the complete stem specification.
Bong parts work together as a system.
For a glass bong, this could be:
Bong → Glass Downstem → Glass Cone Piece
For a traditional bonza bong:
Bong → Grommet → Metal Bonza Stem → Brass Bucket Cone
This means replacing one component may require checking the others.
For example, changing from one glass downstem size to another could also change the compatible cone piece size.
Similarly, a metal bonza stem requires the correct grommet fit and compatible cone.
Billy Mate lists Cone Pieces separately so customers can match replacement components more easily.
Start by identifying your bong.
Glass Bong With Removable Glass Stem
Look for:
- Outer joint size
- Inner cone size
- Stem length
- Diffusion type
Example:
18/14mm, 10cm, slit diffused
Bong With Metal Stem
Look for:
- Bonza stem
- Required length
- Correct grommet fit
- Compatible brass cone
Glass Slider Bong
Match:
- Slider diameter
- Length
- Connection style
Built-In Stem Bong
A separate replacement stem may not be applicable.
Stems can accumulate residue over time because they sit directly in the bong's airflow path.
Removable stems can generally be cleaned separately from the main bong using a compatible cleaning product.
Pay particular attention to:
- Internal airway
- Diffuser holes
- Slits
- Ground glass joints
- Metal stem interior
- Cone connection
A clogged diffuser can change airflow significantly.
Glass stems should also be inspected for:
- Cracks
- Chips
- Damaged joints
If a glass stem is damaged, replacing it is generally preferable to continuing to use damaged glass.
Billy Mate also offers Bong Cleaning Products and compatible replacement cone pieces for maintaining your setup.
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