Pipes and tubes differ in several key ways. Pipes have a nominal diameter that is larger than their actual outer diameter, while tubes have the same nominal and actual diameter. Pipes are used for larger applications that transport fluids over long distances, while tubes are generally used for smaller, more precise applications. Tubes also have more stringent manufacturing requirements than pipes, making them more expensive to produce.

1. Pipe and Tube
“I’m Pipe”
“I’m Tube”
“We are difference!!”
1.Pipe Diameter and Tube Diameter
Pipe diameter refers to a nominal diameter- not actual. Pipe Schedule refers to the pipe’s
wall thickness (you can find the schedule chart and specification). The actual physical outside
diameter is larger than it’s nominal OD.
The diameter of tubing on the other hand refer to the actual outside diameter. In other
words, the actual physical OD of a tube is just the same as it’s nominal OD.
For example: The actual outside diameter of 1 1/4” pipe is 1.625″ – while 1 1/4” tube has a
true 1.25″ outside diameter.
Pipes accommodate larger applications with sizes that range from a half-inch to several
feet. Tubes are generally used in applications that require smaller diameters. While 10-inch
pipes are common, it’s rare that you will come across a 10-inch tube.
2. Wall Thickness Difference
The wall thickness of pipes and tubes is an important factor to tell difference. The
thickness of tubing is often specified by a gauge for thinner thicknesses and for thicker tubing it
is indicated by fractions of an inch or millimeters. The normal range for tubing is 20 gauge,

2. which measures .035 inch, up to a thickness of 2 inches. The wall thickness of a pipe is
referred to as a pipe schedule, which you can find the relevant between pipe schedule and
thickness in millimeter or inch in specification ASME B36.10. The most common schedules are
SCH 20,SCH 40 and SCH 80. Schedule 40 is the most common and 80 is extra heavy. Which
is needed to be noted, the pipe schedule is not set for all diameters; it varies.
For example:
Diameter 8inch/219.1 pipe, pipe schedule is SCH 40 = wall thickness is
0.322inch/8.18mm,
Diameter 12 inch /323.9 pipes, sch 40 refers wall thickness of 0.406inch/10.31mm.
There is no formula between the pipe schedule and wall thickness, the only is to refer to
the ASME B36.10 or relevant standards.
3.Pipes Tolerance & Tube Tolerance
Pipes are usually used for transporting or distributing, then the properties of pressure or
straightness, roundness are strictly specified, the tolerance for pipes is more loose than tubes
comparatively. Here the tolerance refers to diameter tolerance, wall thickness tolerance,
straightness tolerance, roundness tolerance etc.
4.Manufacturing Difference of pipes and tubes
As we mentioned above, tubes will require higher level requirements, consequently, even
from the material producing to the pipe or tube manufacturing process will be different. Tubes
will require much more process, tests, inspection than pipes. The delivery time will be longer,
too. The yield of tubes are comparatively much lower than pipes. Pipe manufacturing is easier
compare to tubes and it’s in mass production
5. Cost & Price
As per to the above, to manufacture tubes will take much more labor, energy, material etc,
so the production cost is surely higher than pipes. And just because the high level requirement
of tubes, the low yield of tubes will also increase the cost and price. While the process of pipes
is easier. And pipes are manufactured in large lot and cut the cost.
6. Use of Pipes and Tubes
Pipes are used for fluids and gases, such as water, oil, gas or propane or as steam pipe,
boiler pipe etc. Just because of this, the outside & inside diameter is the key measurement —
it indicates how much can flow through the pipe. Also that’s the reason why the pressure rating
is so important, because the pressure must be under the transport or distribute pressure range.
Tubes, however, are often put to use in applications that require precise outside diameters,
like with medical tubes, weapon part, industrial parts, cooler tubes, heat exchanger tubes and
boiler tubes. Tubes are usually used in medical area, construction, structure or load bearing

3. etc. This is why the outside diameter is important because it indicates how much it can hold as
a stability factor.
7. Mechanical Properties and Chemical Properties
For pipes the pressure rating, yield strength, ductibility properties are more important.
However, for tubes, the hardness, tensile strength, high precision is the key to high quality.
Those elements like C, Mn, S, P, Si are the main chemical elements for pipes, and there is few
microelements requirements . While for tubing, the microelements are very important to the
quality and process.
Connecting pipes is more labor intensive as it requires welding, threading or flanges and
relevant equipments. Tubes can be joined quickly and easily with flaring, brazing or couplings,
but for this reason, they don’t offer the same stability. Pipe welding is safer than “tube join”.
9. Ductibility
Pipe is available in rigid “joints”, which come in various lengths depending on the material.
Tubing, in particular copper, comes in rigid hard tempered “joints” or soft tempered (annealed)
rolls. Some tubing also comes in rigid “joints” or flexible rolls. The temper of the copper, that is
whether it is a rigid “joint” or flexible roll, does not affect the sizing.
10. Quantity
For long transport or distributing, piping is often used in mass quantity and for long
distance application. So, the order of pipes are usually large. While tubes may be used in small
quantity.
11. Pipe End and Tube End
Pipe ends are usually in plain or beveled so as to welding. while tubes are with coupling
ends or specially end finish, like irregular ends, special screw thread etc.
12. Application
Pipes accommodate larger applications with sizes that range from a half-inch to several feet.
Tubes are generally used in applications that require smaller diameters. While 10-inch pipes
are common, it’s rare that you will come across a 10-inch tube.