317L Round Bar

A hollow section of steel with a round cross-section has been manufactured in the United States since the early 1800s. It is made for the transportation of a wide variety of products, including fluids, gas, pellets, powders, and more. There are many uses for steel pipes, including underground transportation of water and gas, construction to protect electrical wires, and even the transport of liquids and gases. Steel pipes are not only strong, but they also can be lightweight. In addition to this, they are also used for making parts for automobiles, refrigeration units, heating and plumbing systems, flagpoles, and street lamps, just to name a few. This makes them ideal for bicycle frames and other products.

The most important dimension for a pipe is the outer diameter (OD) along with the wall thickness (WT). By subtracting the outer diameter from the wall thickness (WT), the inside diameter (ID) of a pipe is determined, and the amount of liquid it can hold. When we talk about pipe in our industry, we often refer to the pipe as a schedule (ID), such as 2 inches schedule 40 or 14 inches extra heavy. This is what the industry refers to as a pipe. For instance, we can use the walls or schedules below, including the standard (STD), and the XS/XH.  The majority of pipe is sold in lengths of 21 or 42 feet, depending on the manufacturer.

What is Tube?

In engineering, a tube refers to hollow sections that are shaped like rounds, squares, rectangles, or ovals. The tubes are used for pressure equipment, mechanical applications, and instrumentation applications.

There are several raw materials used to make steel tubing, including iron, carbon, manganese, vanadium, and zirconium. Seamless tubing can also be welded, while welded tubing is a solid block of steel that is rolled into a round shape and pierced and stretched to its final length. The same thing is done to play dough when you roll it into a cylinder. If you have extra dough, push your finger through the middle and stretch it out to make it longer. It is produced in the same way, but the raw materials are hot and spinning, and everything is completely machine operated. A welded steel tubing, on the other hand, is made from coils of steel that are welded together. Initially, the coil is slit and rolled up into a round shape, then welded together at the ends. As a result, the tubing can either be simply cut to a certain length and used as round tubes, or it can be altered into other shapes such as square, rectangular, oval, etc. based on the location of the tubing.

It is common for buyers in our industry to refer to the item they are considering as an (OD) and a (WT) in inches or millimeters. The outer diameter (OD) and the wall thickness (WT) of the tube are indicated in inches or millimeters. Tubes can be purchased in a variety of wall thicknesses, such as 11 gauge, 1/4″, 3/8″, or 5/8″. They are available in lengths of 20, 24, 40, and 48 feet, but they can also be manufactured in custom lengths.

What's the Difference Between Steel Pipe and Steel Tube

Steel Pipes and Steel Tubes: What’s the Difference?

Although both steel pipe and steel tube are seamless or welded, they differ significantly in many ways. Although most people believe they are the same, they are not. It doesn’t matter what industry pipe tubes are employed in, they are mostly designed to transport fluids and gases, no matter what they are used for. Pipes are round, whereas tubes can be round, square, rectangular, or oval in shape. Also, tubes can be used to transport fluids and gases. However, tubes, as opposed to pipes, are usually designed to be used for a wide variety of different purposes, such as industrial, medical, aerospace, military, transportation, architecture, and construction in addition to transporting fluids and gases.

Even though these two terms are sometimes used interchangeably, there are a few notable differences between the two, mainly in the way that the material is ordered and tolerated. In spite of being used for structural purposes, tubing’s outer diameter is a crucial dimension in its application. Tubes are frequently used in medical devices that require precise outside diameters, for example.

As a stability element, the outside diameter of a pipe is extremely important since it determines how much weight it can support as a stability element. Pipes are generally used to transport liquids or gases, which is why it is crucial to know how much it is capable of storing. Having a round shape is essential to know how well a pipe flows. Because the pipe is round, it can handle the force that comes from the liquid flowing through it. When you want to purchase steel pipes, you need to understand the details.

Tubes are generally bought by their outside diameter as well as wall thickness, but they may also be ordered by the ID and the wall thickness as well as by their OD and ID. Though tubing has three dimensions, only two of them can be defined with tolerances. Tubing is frequently ordered with tighter tolerances and standards than pipe and is kept to them. The NPS standard is commonly used to order pipe, which requires both a nominal diameter and a schedule number to be specified. There are several ways in which pipes and tubes can be bent, cut, flared, and manufactured.


There are a few essential characteristics that distinguish tubes and pipes:

Shape :

In general, pipes are round. Tubes are available in square, rectangular, and round shapes.


In tube ordering, outside diameter and wall thickness are typically specified. Tubing has stricter tolerances than pipe. The pipe is usually ordered by NPS, or nominated steel pipe size, with specifications such as wall thickness and diameter.


Unlike pipe, tubes can be bent and coiled without causing severe deformation, wrinkling, or breaking, as long as you use special tools. Copper and brass can be bent and coiled without causing severe deformation, wrinkling, or breaking.

Types of Metal tubes

In the case of tubes, they can either be cold-rolled or hot-rolled. Only hot rolled pipes are used and both of these items can be galvanized.


Generally, pipes are used for applications requiring large diameters. Tubing is frequently used when small diameters are required.


The pipe is not as durable as tubes. Tubes are stronger and more durable in applications that require them.


A variety of shapes, sizes, and types of tubes are available made from copper and brass, as well as rigid and flexible forms. Because of their rigidity, pipes are made from copper and brass and are strong, durable, long-lasting, and versatile.

Pipe diameter

Tubes with small diameters and pipes with large diameters are two types of tubes. A tube with a small diameter has a diameter of between 3/16″ and 5/8″ ( = 3-16 mm), whereas a pipe with large diameter has a diameter of 15-1500 mm (= 1 / 2-60″). As well as falling within this range, these pipes are available in a wider range of sizes, but their usage is much less common.

Size standard features

For tube OD, For example, 1 / a 4 “(6.25 mm) od tube is a tube with an outer diameter of 1 / 4”. Tube pays attention to the accuracy of outer diameter, because the tube is connected by the ferrule, and pipes with the same outer diameter can be connected with ferrule. For pipe Nominal diameter Size dn Indicates the pipe diameter specification. If DN50 means 2 “pipe, it can be expressed as Φ 57 × 3.5mm Φ fifty-seven × three point five m m It can also be expressed asΦ 60 × 3mm Φ sixty × three m m。 Because the pipe is mainly used for transporting fluid and has high requirements concerning the internal pressure capacity of the pipe, it pays attention to the thickness of the wall.

Market abbreviation

Generally, tubes on the market are termed thin-walled tubes because of their thin walls. Typically, these tubes are around one to two millimeters thick (inch or mm), and the standard thickness for pipes is the wall thickness serial number (abbreviated as Sch. No.). It is generally accepted as a standard thickness for pipes, and the serial number (abbreviated as Sch.) indicates the thickness of the wall. In general, wall thickness is indicated by the serial number (abbreviated as Sch. Generally, it is necessary to use the schedule number, also known as the pressure resistance grade number, to identify the wall’s thickness. As a result, it is described by the schedule number. In a schedule number such as Sch. XXS, different pipe diameters or materials may have their own standard wall thickness series, while pipes with the same Sch. No. but different pipe diameters or materials may have different wall thicknesses.

Connection mode

The thin walls of tubes make threading on them impossible, so the tube is connected with a ferrule, also known as the crimping connection, after annealing. Pipes can be connected in three ways in the pipeline industry: flanges, threads, and welding, and most of them use flange connections, whereas threaded connections can be used in low-pressure circumstances.

Connection features

Tubes with identical or equal outer diameters can be connected using ferrules, which are fast and can be removed many times. Each flange and thread must be marked with a standard number, such as two yd – ANSI-150-rf, for instance.

The pipe is bent

The pipe joint can be bent directly according to the needs by choosing the right angle, which reduces the potential leakage points. It can also be bent directly in accordance with the bending angle (without the use of pipe joints). In general, elbow pipe joints are used as connections when bending (they are usually threaded, but should have an arched thread if the pipe has to be bent).


The length of a 6m pipe can be cut as many times as necessary during construction, according to the specific site conditions.


Among the many uses of tubes, there are heat tracing and thermal insulation used in measurement pipelines, pneumatic signals in instrument systems, and sample pipelines used in online analyzers and online environments. In addition to process pipelines and utility pipelines, tubes are also used in a significant number of other applications.

Connection requirements

This ferrule can be used with double ferrules or single ferrules. Neither ferrule should be connected to double ferrules or single ferrules, each should be connected to the ferrule independently.

Pipe characteristics

There are many different types of pipes being used in the transportation industry, with stainless steel tubes, copper tubes, and brass tubes being the most common types of tubes used. Seamless steel pipe and seamless steel tube are chosen according to the intended purpose.


Different Diameters

The distinction between steel pipes and steel tubes can be broken down into a dozen different types. The first thing you need to keep in mind is that they have different diameters that are measured differently. When it comes to determining the size of the pipe, it is important to remember that the inside diameter of the pipe is the determining factor.

The outside diameter of tubes is used to calculate their length. In general, steel pipes are used for larger applications while tubes are mostly used for smaller applications.

Another important distinguishing factor is the shape and thickness of the wall. Generally, steel pipes are supplied in the form of round sections. It is also possible for tubes to be round as well as square or rectangular.

It is vital to recognize those factors since they directly relate to the thickness of the wall. In order to determine the strength of a steel pipe or tube, it is necessary to calculate the thickness of the wall. Depending on the use of a steel pipe or tube, its strength will vary.

Tolerance and Application

It is important to keep in mind that the main difference between steel pipes and steel tubes is the tolerance and the process of application. In most cases, pipes are used to transport or disperse gases and liquids. In order to ensure the safety of the pipe, it is crucial that the capacity and tolerance of the pipe are known.

It is common to use steel tubes for structural purposes. As an example, they are used to manufacture pivots for agricultural equipment, such as pivots used in the field of agriculture.

It is also important to note that the manufacturing procedures play an important role in the difference as well. There is no doubt that tubes require a more in-depth level of processes, tests, and inspections than other types of products.

As a result, the distribution method is delayed. It is also noteworthy to mention that steel pipe applications are more accessible and are often produced in large quantities.

Aside from that, producing steel tubes is more costly due to the fact that it requires a large amount of labor, energy, and materials. As a result, the construction of pipes is more manageable, thereby reducing the item’s cost.


Depending on the material that is used to make each pipe, there is an increase in price as a result. Pipes are primarily made up of carbon steel and low alloy steel.Meanwhile, tubes can be made of:

  • Steel
  • Aluminum
  • Brass
  • Copper
  • Chrome
  • Stainless steel

There is also a difference in the chemical composition of each object. Pipes are primarily composed of the following chemical elements:

  • Carbon
  • Manganese
  • Sulfur
  • Phosphorus
  • Silicon.

When it comes to tubes, smaller elements play an important role in the process as well as the quality.

It is very important for those who work in the manufacturing industry to be able to distinguish between steel pipes and tubes. A number of factors, such as diameter, structure, wall thickness, use, cost, and material, all contribute to the differentiation of different types of metals.

Mokshi Shah
Mokshi Shah