Understanding Pipe Vs Tube Differences And Size Chart

It’s difficult to know about a pipe vs tube actual difference. A pipe is a round, hollow, tubular structure used to carry and transfer gases or fluids. The tube is of various-shaped hollow sections used for structural projects like medical devices and car frames.

Pipe and tube are both used interchangeably and misunderstood as the same material with similar use purposes. That’s actually not correct. Even the most experienced industry people got confused between these two terms. Both are elongated hollow cylinders; how they are different and what they distinctly serve are real things to ponder.

Pipes are vessels that efficiently transfer gasses and liquids, while tubing or tube is a hollow section used for structural projects in various industries. When it comes to pipe vs tube sizing, both are measured differently. The pipes’ main purpose is transferring gasses or liquids, so their size gives a rough idea of their conveyance capacity.

In tubes, the outside diameter is the most important dimension which makes it best to use for structural applications in construction and medical devices where precision in outside diameter is required to measure for known stability ability. This is just the start; to clear your misconceptions, you need a detailed comparison between pipe vs tube. So, give our detailed analysis and comparison of pipe vs tube a read.

What is pipe?

Pipes are hollow tubular vessels with round cross sections for the carriage of various products, from fluids and gases to powders and pellets. These vessels’ main use is in piping systems and pipelines where they transport products efficiently. They are designated using two key measurements Nominal Pipe Size with short form NPS and Schedule which is commonly known as wall thickness (WT). American National Standards Institute (ANSI) created this North American set of standard sizes named NPS for pipes. The most important thing is to not confuse it with thread standards like NPT and NPSC, which commonly happens.

What is Tube?

Tubes come in different hollow sections, from round and rectangular to square and oval, which are used for structural purposes. Its size is specified by outer diameter, which is important exact number and wall thickness. In tubing, the stated OD is within very close tolerances to a measured OD. In the case of copper tubing, ⅛ inches measured OD is larger in size than the stated OD. Measured and stated ODs are exact or within very close tolerances of +/- 0.04 inches in stainless steel, aluminum and steel tubing.

Tubing has tighter manufacturing tolerances, which makes them more expensive than pipes. Their outside diameter and wall thickness generally specify tubes. According to the needs of different industries, they are also ordered by OD and ID or by ID and wall thickness. Wall thickness determines and influences the strength of tubes.

The thickness is represented by a gauge number, where smaller gauge numbers directly mean larger outside diameters. It’s important to note that the inside diameter is a theoretical measurement.

Industries Use Pipe And Tube

Tube	Pipe	Both Tube & Pipes
Aerospace	Oil/Gas	Brewery/Distillery
Food/Dairy/Beverage	Wastewater	Treatment Chemical/Petrochemical
Biopharmaceutical/Pharmaceutical	Plumbing	Power Generation
Semiconductor	Fire sprinkler systems	Pulp/Paper
Medical	Sewer and drain lines	Shipbuilding

The Difference Between The Pipe Vs Tube

We have discussed pipes and tubes in detail; it’s time to check the difference between them. It helps you understand which one you need for your industrial needs.

Pipe Vs Tube: Difference In Dimensions

Although tubes and pipes share some similarities, the most notable difference lies in their sizing and measurement methods.

Check Tube Size

Tubes are measured by their wall thickness and outside diameter (OD). Since tubes are often used in structural applications, the OD is the key dimension to consider. The outside diameter is measured in exact sizes, meaning a 2” tube will have an outside diameter of precisely 2 inches, measured from one outer edge to the other. Even if the inside diameter (ID) changes, the outside diameter remains constant.

Check Pipe Size

The outer diameter ‘OD’ of the pipe and wall thickness are important dimensions for measuring pipe size. Find a pipe’s inside diameter by looking up its outside diameter and wall thickness (based on its NPS and Schedule) in a chart, then using the formula:

Inside Diameter Of A Pipe = Nominal Outside Diameter – 2 * Schedule

ID = OD – 2 * WT

The inside diameter helps in finding the capacity of the pipe for carrying and transferring liquid substances.

For pipes ranging from 1/8 inch to 12 inches, the NPS relates to a standardized nominal outside diameter ‘OD’, which isn’t the same as the actual measured OD. Things change for larger pipes (14 inches and above); their measured OD matches the nominal size.

We see a common misconception among professionals like plumbers and engineers that NPS represents the inside diameter of smaller pipes. This misunderstanding likely stems from the historical development of the standard.

The original standardized OD was chosen so that, with a typical wall thickness for the time, the resulting ID would be close to the nominal pipe size. Take a 3-inch Schedule 40 NPS pipe as an example. Its OD and wall thickness combine to give an ID that’s roughly 3 inches. It’s crucial to remember that the nominal OD remains constant, regardless of changes in wall thickness.

Pipe Vs Tube: 7 Other Differences Based On Characteristics Of Pipe And Tube

Shape

Pipes are round because of a specific reason, but tubes can be of different shapes, from rectangular and square to round. They are specially designed in this way for efficient transportation of fluid or gases. The circular cross-section in pipes allows even pressure distribution and lowers the risk of weak points. These weak points cause leaks or bursts.

When it comes to shapes, tubes are more versatile than pipes. They come in rectangular, square or triangle shapes other than the circle. This variety of shapes makes the tube suitable for structural applications and contributes to the overall strength and stability of the framework.

Telescoping Abilities

Tubes have telescoping abilities. Therefore, these are perfect for applications where different pieces of material are cased inside one another. There is a flash weld inside the tube, but the pipe doesn’t have a flash weld.

Rigidity

Pipes are rigid, and there is no way to shape them without any special equipment. Their rigidity is necessary for primary functions such as the transportation of fluids and gases under pressure. Pipes can withstand high pressure and resist deformation, maintaining a reliable and consistent flow.

Tubes are typically rigid except copper and brace tubes because they are relatively easy to shape. Therefore, tubes are ideal for structural and architectural applications because they are crucial for maintaining stability and strength.

Metal Types

Both pipes and tubes are able to galvanize. When it comes to metal types, tubes are available in both cold-rolled and hot-rolled steel. The pipe is available only in hot-rolled black steel.

Size

Pipes are available in large sizes as compared to tubes. Large-diameter pipes give them a better flow capacity that is essential for plumbing, industrial and municipal infrastructure projects. Tubes have a small diameter that helps to provide consistency in their measurement. This measurement consistency is helpful in applications where exact dimensions and tight tolerance are needed, such as in structural frameworks, medical devices and mechanical components. Tube cutting machines help in getting your desired tube sizes according to your industrial needs.

Strength

When it comes to strength, tubes are better than pipes. Tubes’ strength makes them a perfect choice for applications that demand structural integrity and load-bearing capacity. If you are opting for a more reliable and durable structure, tubes should be your choice.

Cost

When it comes to cost, pipes are affordable, while tubes are somewhat expensive due to their high manufacturing requirements, like accurately achieving precise OD than nominal OD for pipe.

Pipe Vs Tube Size Chart

Standard Steel Pipe Size Chart

NPS (in)	OD (in)	ID (in) – SCH 40	Wall Thickness (in) – SCH 40	ID (in) – SCH 80	Wall Thickness (in) – SCH 80
1/8	0.405	0.269	0.068	0.215	0.095
1/4	0.54	0.364	0.088	0.302	0.119
3/8	0.675	0.493	0.091	0.423	0.126
1/2	0.84	0.622	0.109	0.526	0.147
3/4	1.05	0.824	0.113	0.742	0.154
1	1.315	1.049	0.133	0.957	0.179
1-1/4	1.66	1.38	0.14	1.278	0.191
1-1/2	1.9	1.61	0.145	1.5	0.2
2	2.375	2.067	0.154	1.939	0.218
2-1/2	2.875	2.469	0.203	2.323	0.276
3	3.5	3.068	0.216	2.9	0.3
4	4.5	4.026	0.237	3.826	0.337
6	6.625	6.065	0.28	5.761	0.432
8	8.625	7.981	0.322	7.625	0.5
10	10.75	10.02	0.365	9.75	0.593
12	12.75	11.938	0.406	11.374	0.688

Tube Size Chart

Tube Size (in)	Outside Diameter (in)	Wall Thickness (in)	Inside Diameter (in)
1/8	0.125	0.028	0.069
1/4	0.25	0.035	0.18
3/8	0.375	0.035	0.305
1/2	0.5	0.049	0.402
5/8	0.625	0.049	0.527
3/4	0.75	0.065	0.62
7/8	0.875	0.065	0.745
1	1	0.065	0.87
1-1/4	1.25	0.065	1.12
1-1/2	1.5	0.083	1.334
2	2	0.109	1.782
2-1/2	2.5	0.12	2.26
3	3	0.12	2.76
4	4	0.12	3.76

Conclusion

Knowing the difference between pipe vs tube is important for selecting the right material for your project. Pipes are ideal for transporting fluids and gases, but tubes excel in structural applications where precision is important. Knowing how they differ in shape and size measurement with industry use helps you make informed decisions and avoid costly mistakes. For all your pipe and tube process requirements from manufacturing to cutting and welding to bending, BOBO machines are your best help to fulfill your all requirements.