Difference Between Schedule 40 and Schedule 80 

First, let’s learn the Nominal Pipe Size (NPS)
Nominal Pipe Size (NPS) is a North American set of standard sizes for pipes used for high or low pressures and temperatures. Pipe size is specified with two non-dimensional numbers: a nominal pipe size (NPS) based on inches, and a schedule (Sched. or Sch.).

Please see the dimension chart below.

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What is the difference between Schedule 40 pipe nipple and Schedule 80 pipe nipple?

Stainless Pipe nipples are made by stainless steel pipes.

The main differences between schedule 40 and schedule 80 pipe are wall thickness, inside diameter, and weight. At a given nominal pipe nipple size, Schedule 80 pipe nipple will have a thicker wall, a smaller inside diameter, and a heavier weight.
If you are new in pipe industry, why you always see a schedule 40 or 80 steel pipe everywhere? What kind of material for these pipes?
As you have read above articles you know that Schedule 40 or 80 represent a pipe wall thickness, but why it always been searched by buyers?
Here is the reason:
Schedule 40 and 80 steel pipe as the common sizes that required in different industries, because of the generally pressure these pipes bear, they are always been asked for a large quantity.

Sch40 VS Sch80 Summary:

Weight: Schedule 40 pipe nipples weigh less than Schedule 80 pipe nipples.
Price: As Schedule 80 pipe nipples consist of more materials, the price is considerably higher than Schedule 40 pipe nipples.
Pressure: If there is a need for a high water temperature or high-pressure pipe, Schedule 80 is the best as it can withstand a greater pressure and temperature than Schedule 40 pipes.
Usage: Although both pipes are used in construction, Schedule 40 is more commonly used.
Schedule 80 pipe nippless are used where the pipe nipples have to be exposed. But if there is no need for any extra strength, Schedule 40 pipe nipples are sufficient.

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