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″.
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.