Skip to Content

What Size Thread Is a Propane Tank? (Explained)

Propane tanks are important for various operations in our everyday life. From cooking to generating power, this is important for everyone. There are various sizes of propane tanks available in the market right at this moment. 

The size that you will need will be based on your requirement and need.

You may ask what thread size a propane tank is. Let us find the answer that you are looking for and provide you some insight about this matter:

What size thread is a propane tank?

In general, the thread size of a propane tank is ¾” – ⅜” on average. There will be around 14-18 threads per inch. But this will be based on the size of your propane tank. If the size of the propane tank is big, the size of the thread will vary based on that as well.

Propane tanks usually come in different sizes of thread. This will vary based on the size of the propane tank. If the tank size is small, the size of the thread will be small. If the tank is big, the size of the thread will be big.

Whatever the size is, it is mandatory to set whatever you want to use on the thread properly. You must set it according to the instruction of the item that you are installing. Besides, to ensure that whether or not it is properly seated, you can use thread sealant for the propane tank.

You may want to know the thread size of some particular sizes of propane tanks. Here are popular sizes of the thread of some propane tanks that we think are essential for you to know:

1 lb propane tank:

The thread size of a 1 lb propane tank is 1/4”. This is a universal size for all 1 lb propane tanks. This fits all kinds of bottles, hoses, and regulators. Therefore, this is an ideal thread size for a 1 lb propane tank.

20 lb propane tank:

The 20 lb propane tank has a thread size of 3/4”. It can be said that both 15 lb propane tanks and 20 lb propane tanks have the same thread sizes.

100 lb propane tank:

A 100 lb propane tank will have a thread size of around 3-1/2”. 100 lb propane tanks are basically used at homes and commercial buildings. These tanks are huge and carry a lot of propane.

What size thread are these propane tanks?

Let’s walk through the section to know what size thread is these propane tanks –

Blue Rhino propane tank thread:

The size thread of the Blue Rhino propane tank is 3/4″. Blue Rhine sales propane tanks within 15 lb. Therefore, it uses the universal size thread of any 15 lb propane tank which is similar to any 20 lb propane tank as well.

Coleman propane tank thread:

The size thread of the Coleman propane tank is 1/4”. Coleman sells small 1 lb rechargeable and non-rechargeable propane tanks for small stoves for camping and small use cases. Therefore, it has a small size thread.

Forklift propane tank thread:

Forklift propane tank has 3/4″ size threads. Most forklift propane tank comes in either 33 lb or near 42 lb. Both of them have the universal thread size of around 3/4″ lb.

Small propane tank thread:

The small propane tank thread size is 1/4″. These propane tanks are used for mainly camping and using it in small portable stoves. These propane tanks are lightweight and can be carried anywhere without any hassle.

Standard propane tank thread:

3/4″ size thread is used in standard propane tanks. Mainly 20 lb propane tanks are used as a standard propane tank. These tanks usually come with 3/4″ size threads which are universal in almost all propane tanks.

Grill propane tank thread:

Grill propane tank uses 3/4″ size thread. Grill propane tanks are basically a rename of standard propane tanks. But this is a compact version of the 20 lb propane that we see. It comes in a 15 lb size. 

These are also rechargeable or non-rechargeable according to our needs. But rechargeable ones are expensive.

Disposable propane tank thread:

Disposable propane tank comes with 1/4” size thread. These propane tanks come in various sizes. But it is seen that most of them come in 1 lb – 6 lb. All of these have the same universal size threads.

Which way do the threads turn on a propane tank?

Generally, the threads turn counterclockwise on a propane tank. A propane tank is basically a combustible gas. Therefore, based on, if the gas is combustible or not, the way that threads turn on a tank is different.

Non-combustible gas tanks thread that turns clockwise. Whereas combustible gas tanks have a counterclockwise thread. So, if you want to connect a propane tank to any connection, you will have to turn it counterclockwise so that it can attach.

Are all propane fittings reverse thread?

Yes, all propane fittings are reverse threads. All threads in the whole world mostly use clockwise threads. This makes opening any connection easy and helps to disconnect any thread without any hassle.

But there are some threads that do not maintain this. Among those handful exceptions, propane tank threads are one of them. Propane tanks use reverse thread to connect any connection. This is to prevent any kind of accidental disconnect issue by the user.

Why are propane tanks threaded backward?

Propane tanks are threaded backward because it prevents any unwanted disconnection of the regulator from the tank valve. Propane tanks are dangerous while operational. Especially when you are using it. 

Any kind of accidental leakage due to mistakenly opening any connection may lead to propane leakage and lastly fire risks.

To prevent this, propane tank producers use a safety approach that is approved by experts. This is called the reverse thread method. You cannot open by turning it counter clockwise. You will have to open any connection by turning it clockwise.

Another reason is to prevent the connection of combustible gas to any non-combustibleconnection. As this is reversely threaded, you cannot accidentally connect any propane tank on any non-combustible line. 

Therefore, this ensures the safety and prevents mistakes that you may make.

This helps to prevent any accidental disconnection by you and any other people who will use it. Therefore, this ensure the safety of the user and lastly you.

What type of thread sealant for propane fittings?

Water-based non-toxic thread sealant with UL approval is an appropriate thread sealant for propane fittings. There are various solutions available as a thread sealant. But among all of them, the water-based non-toxic sealant is the best among all.

There are various brands available for this kind of sealant. These sealants are mostly non-toxic. Most of them have UL approval for the best possible application. These sealants help to prevent any kind of leakage in the system as well as any kind of unwanted removal of any component.

Thus, this is an appropriate thread sealant choice.

Final thoughts

The size thread in a propane tank is an average of ¾” – ⅜”. There will be 14 – 18 threads based on the size thread diameter. The size thread will vary based on the size of the propane tank you will use. So, you will have to check the specification of the propane tank for the appropriate size.