Many people often ask “What is the difference between tubing and pipe?” I am going to hit some of the high points of each.
Pipe is sized by the inside diameter or the I.D. of the pipe, this will be discussed a bit more later. To confuse matters a bit the wall thickness of the pipe is described by the schedule of the pipe. The three common schedules are schedule 10, schedule 40, and schedule 80 or extra heavy. Schedule 40 by far is the most common wall thickness.
The schedule 40 wall thickness is not a set dimension for all sizes of pipes. 1″ schedule 40 pipe has a wall thickness of .133″ and 2″ schedule 40 pipe has a wall thickness of .154″.
I said earlier that pipe is sized by the inside diameter, at least that is what I have always been taught. I am going to look at 2″ pipe:
2″ schedule 10 pipe has a I.D. of 2.157″
2″ schedule 40 pipe has a I.D. of 2.067″
2″ schedule 80 pipe has a I.D. of 1.939
The outside diameter or O.D. of 2″ pipe is 2.375″ for all three schedules.
Pipe is commonly available in carbon steel in two types continuous buttweld and electric resistance welded (ERW).
Now we are going to hit the high points of tubing, tubing is available in many different types of materials and wall thicknesses, and sizes actually make sense.
Tubing is sized by the outside diameter or O.D. 1″ tubing actually measures 1″ on the outside diameter (within a few thousands of an inch.) Tubing wall thicknesses are measured in gauges up to a point then convert to fractions of an inch, some wall thicknesses are even measured in millimeters.
Outside diameters range from 1/8″ and beyond 12″. Wall thicknesses range between 20 gauge (.035″) and 2″ thick.
Tubing is available in many types of materials, some including: mild steel, steel alloys (4130), aluminum (6061, 6063, 2011, 3003, with various heat treating), brass, copper, stainless steel, and more.
Tubing is also available in many types of drawing and forming processes some including: (cold drawn seamless, buttweld, electrical resistance welded ERW, drawn over mandrel DOM, hot finished seamless) and others.

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8 users responded in this post
can i know what is the different between stainless steel schedule 10,schedule 40 and schedule 80 pipe and its application on where it were applied for
thank you
The difference between schedule 10,40 and 80 stainless steel pipe is the wall thickness. Schedule 10 has the thinnest wall and schedule 80 has the thickest wall. The wall thickness varies within each schedule depending on the diameter of the steel pipe. Smaller diameters have a thinner wall. Larger diameters have a thicker wall.
Common types of stainless steel that are used in welded pipe are 304 and 316. 304 stainless steel is the most common in use. It is easily welded by most common methods as well as being corrosion resistant to many chemicals and industrial atmospheres. 316 stainless steel stands up better to corrosion and pitting. It also has a higher strength at elevated temperatures. It is most commonly used in chemical equipment and marine applications.
If you would like actual wall thicknesses, I would need to know the diameter of the pipe.
Thanks for your question. Tom
Threading given is 3 ince NPT with schedule 40 on 316 Stainless Steel. Pls inform the pipe thickness in milimeters.
Above article was helpful. Now, please highlight what is the difference between sheet and plate?
Thanks for answer.
does this means that the O.D of pipe is fix and the sch. changes the I.D. i.e. thickness of pipe
IN NPS (NOMINAL PIPE SIZE) ID AT MOST EQUAL TO SPECIFY SIZE BUT OD WILL BE CHANGED DEPENDS ON SCH OR CLASS
what is the difference between sheet and plate?
Fermin,
Plate is steel sheets that are 3/16″ or thicker. Sheet is a thinner in width. Thanks for the question!
Tom
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