Welding Tank Size Chart: Understanding Cylinder Sizes

Written By: Liam Bryant

Reviewed By: Russell Egan

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Understanding the correct welding tank size for your project can significantly impact efficiency and cost. This comprehensive guide provides a welding tank size chart, explores popular gas bottles, and advises on which sizes are best suited for different types of welding.

80 cu/ft 75% Argon 25% CO2 Welding Gas Cylinder

80 cu/ft 75% Argon 25% CO2 Welding Gas Cylinder

  • Most Popular Size and Gas
  • 10 year hydrotest date stamped
  • Meets DOT and/or ISO regulations
  • DOT number is stamped on the tank
125 cu/ft 75% Argon 25% CO2 Welding Gas Cylinder

125 cu/ft 75% Argon 25% CO2 Welding Gas Cylinder

  • 10 year hydrotest date stamped
  • Meets DOT and/or ISO regulations
  • DOT number is stamped on the tank
125 cu/ft 100% Argon Tank Welding Gas Cylinder

125 cu/ft 100% Argon Tank Welding Gas Cylinder

  • 10 year hydrotest date stamped
  • Meets DOT and/or ISO regulations
  • DOT number is stamped on the tank

Welding Tank Size Chart

Below is a table listing the most common welding tank sizes and their respective volumes. This can be used as a reliable tank chart for your projects.

NameTank Size (Cubic Feet)Volume (Liters)Expected Welding Time (Hours)
MC10 cf2830.5
B20 cf5661
R40 cf11332
Q80 cf22654
S125 cf35416.25
K251 cf711212.55
T330 cf934516.5

The welding time in the table above is based on a standard consumption of 20 cf per hour.

Remember, these welding times are approximate and depend on your exact flow rate and the efficiency of your welding process. For instance, more experienced welders who can maintain a consistent bead with less stop/start action will typically use less gas compared to someone still perfecting their technique.

co2 welding gas bottle tank size

Types of Gas Bottles for Welding

Welding requires different types of gases, and knowing which to use can be just as important as understanding cylinder sizes. Let’s explore the most commonly used gases:


Argon is primarily used in TIG welding and MIG welding aluminum. I remember when I first tried out MIG welding and found that using pure Argon gave me a much smoother and cleaner weld than other gases.


CO2 is the cheapest welding gases and provides deep penetration, which is excellent for welding thick steel. However, it may result in a rougher weld than Argon or an Argon/CO2 blend.

Argon/CO2 Blend

This is a popular gas blend, especially for MIG welding steel. I’ve found that using a 75% Argon / 25% CO2 blend gives me excellent control over the weld and results in less spatter than pure CO2.

Popular Welding Tank Sizes

40 cf

The 40 cf size is quite popular, especially among hobbyists and DIY enthusiasts due to its portability. It’s great for your small projects around the house or garage.

80 cf

The 80 cf cylinder size is a middle-ground option. It offers more gas than a 40 cf tank while maintaining a reasonable size and weight. It’s ideal for medium-sized projects.

125 cf

The 125 cf cylinder is an excellent choice for professional welders or for those handling larger projects. I’ve used this size when I’ve had long, continuous welding jobs, which has served me well.

Welding Tank Material: Steel vs Aluminum

When it comes to the material of the welding tank, you have two main options: steel or aluminum. Steel tanks are often cheaper and more robust but are heavier and more prone to rust. On the other hand, aluminum tanks are lightweight and rust-resistant but more expensive.

Personally, I prefer aluminum tanks due to their longevity and ease of transport.

Steel Tanks

Steel tanks are incredibly durable, making them a popular choice in various industries, including welding. Because steel is robust and resistant to puncture, so it provides extra safety when dealing with pressurized gases. This strength also means that steel tanks are more likely to stand up to the rigors of a busy work environment or a crowded workshop.

One time, my steel tank had a minor mishap, falling over in my truck bed. It took the fall without a dent, a testament to its durability.

Steel tanks, however, have a couple of significant downsides. The first one is their weight. Because steel is much heavier than aluminum, steel gas cylinders can be more difficult to transport and maneuver. Depending on the cylinder’s size, this could lead to strain or injury.

The second downside is susceptibility to rust. Over time, exposure to moisture can cause a steel tank to rust. While this doesn’t necessarily compromise the tank’s ability to hold gas, it can make it look old and uncared for. More importantly, it could lead to a rough surface that might injure hands or snag on other materials.

Aluminum Tanks

Aluminum tanks, on the other hand, are known for being lighter than their steel counterparts. This weight difference can make a big difference when transporting and maneuvering the tank, particularly for DIY welders who might not have access to equipment like gas cylinder hand trucks.

I once replaced my steel tanks with aluminum ones and noticed how much easier it was to move around my shop. This ease of movement can be vital for those with back problems or other physical limitations.

Another significant advantage of aluminum is its rust resistance. Unlike steel, aluminum doesn’t rust when exposed to moisture, making it a more attractive option for those living in damp climates or those who want to maintain a clean, professional appearance in their workshops.

One potential downside of aluminum tanks is that they are generally more expensive than steel ones. However, when you consider the benefits – ease of transport, resistance to rust – it could be a worthwhile investment, especially if you plan on using your welding gas tanks for a long time.

How Long Does a Welding Tank Gas Bottle Last

The length of time a welding gas bottle will last you depends on several factors. These include the type of welding process you’re using (MIG, TIG, etc.), the gas flow rate, the gas cylinder size, and the efficiency of your welding technique.

Each welding process requires a different flow rate, typically measured in cubic feet per hour (cfh). For example, MIG welding generally requires a flow rate between 15 and 25 cfh, while TIG welding might require 10-15 cfh. The higher the flow rate, the faster you use your gas.

The gas cylinder size you’re using will also play a crucial role. Larger cylinders hold more gas, so they’ll last longer. For instance, with a flow rate of 20 cfh, a 125 cf tank would give you approximately 6.25 hours of welding time. On the other hand, a smaller 40 cf tank would provide just 2 hours at the same flow rate.

However, these figures assume continuous welding, which we all know is not how welding always works. Your gas may last significantly longer with stops and starts, set-up times, and breaks. For example, a day of intermittent welding might see a 125 cf tank lasting several days, or even a week, depending on the specific welding conditions.

How Much Gas Do I Need as a DIY Welder?

As a DIY welder, the amount of gas you’ll need will largely depend on your specific welding projects. Factors to consider include the project size, the welding process you’re using, and how often you weld.

Small projects and infrequent welding sessions may only require a smaller gas cylinder, such as a 20 or 40 cf tank. These tanks are also more portable and easier to handle, making them an excellent choice for DIY welders with limited workspace.

On the other hand, if you’re undertaking larger projects or welding more frequently, a bigger tank, such as an 80 or 125 cf cylinder, is a better choice. Although these tanks are larger and heavier, they provide more gas, which means fewer trips to the refill station.

The type of welding you do also plays a role. MIG and TIG welding, for example, generally require different gas flow rates, which will affect how quickly you go through your gas. As a rule of thumb, a higher flow rate or extended welding time will require more gas.


Knowing your cylinder sizes and gases is crucial for efficiency, cost-effectiveness, and safety. By understanding the specifications and available sizes of welding gas cylinders, you can tailor your welding setup to fit your needs, whether for a DIY project or industrial welding jobs.

You will likely also need an oxy-acetylene tank for your cutting needs.