There isn't one correct answer to which Festo pneumatic tubing you should order. Anyone who says 'just use nylon' or 'just use polyurethane' is probably describing their own machine, not yours. The right material depends on how the line runs, how much it moves, what it touches, and what happens if it fails.

I'm a maintenance planner and order approver. I've been handling Festo component orders for seven years—well, six and a half, if I include only the years I actually kept records. I've personally made and documented 14 significant specification mistakes. Total wasted budget: roughly $28,000, maybe $29,000 if you count the expedited shipping. I now maintain our team's ordering checklist so other people don't repeat my errors.

One thing before I get into the material details: my experience is based on typical factory automation—packaging lines, material handling, robotic cells. If you're in pharma cleanrooms or aggressive chemical processing, your requirements are stricter. Some of my shortcuts won't apply there. I'll tell you where to look instead.

The material question: PA nylon vs. polyurethane

Start with this: 'plastic' is not a useful word for choosing pneumatic tubing. PA nylon and polyurethane are both plastics in the broad sense, but they behave differently in a machine.

PA nylon—polyamide—is a thermoplastic. It's harder, holds its shape, and resists abrasion from clamps and cable ties. In the Festo catalog, this type is commonly called nylon tubing. It's a good default for lines that stay in place.

Polyurethane, often shortened to PU, is also a polymer, but it's much more flexible. It bends without taking a permanent set and it survives repeated flexing better than nylon. In the Festo catalog, this type is typically called PU tubing.

Why does this matter? Because the two materials fail in different ways. Nylon that flexes repeatedly can develop stress cracks. Polyurethane that sits in a hot, oily environment may soften or react with chemicals it isn't rated for. Choosing between them means deciding which failure mode you're trying to avoid.

What about 'plastic syringe'?

One of the strange search terms that leads people to this topic is 'plastic syringe.' I think the connection is material identification: someone is trying to figure out whether a syringe is PA nylon, or whether a plastic syringe can be used in an air line. Most plastic syringes are polypropylene, not nylon. Polypropylene is fine for many low-pressure lab applications, but it's not automatically compatible with compressed air fittings or lubrication fluids. If you're using a syringe in a pneumatic circuit, check the material grade and pressure rating instead of assuming 'plastic' means 'nylon.'

Is silicone made of plastic?

Another common question is 'is silicone made of plastic?' Short answer: no. Silicone is a synthetic elastomer, not a thermoplastic. It's a polymer made from silicon, oxygen, and carbon, and it behaves more like rubber than plastic. That distinction matters. Silicone tubing is useful for food, medical, and high-temperature applications, but it isn't a drop-in replacement for standard pneumatic tubing. It has higher gas permeability, different compression set, and it doesn't always hold the same way in compression fittings. If a supplier suggests silicone as a 'more flexible' version of nylon or PU, ask for a datasheet before you order.

Three scenarios: which Festo tubing should you order?

Here is how I look at most tubing requests. There are three common scenarios, and each one favors a different material.

Scenario 1: Static, protected lines (PA nylon)

If the tubing runs from a valve manifold to a fixed point, along a machine frame or inside a cable tray, it doesn't flex very much. In that case, PA nylon is my default. It holds its shape, doesn't sag as much, and resists wear from clamps. It also tends to be less expensive than PU, but the real value is reliability: it won't move around and rub against nearby parts.

Contrary to what some technicians think, 'harder' does not mean 'better everywhere.' Nylon is stiff, and stiffness is only an advantage when the tube is essentially static. On a moving axis, the same stiffness becomes a weakness. If the surrounding machine vibrates constantly, watch the line in operation before assuming it's static.

Scenario 2: Moving or flexing lines (Polyurethane)

If the tubing is attached to a robotic arm, a linear axis, or any component that moves throughout the day, choose polyurethane. Searching for 'Festo polyurethane tubing' is a good start, but the exact part number matters because not every PU has the same flex rating. This is the scenario where I've made my most expensive mistake. In 2021, I ordered 300 meters of what I thought was flexible Festo tubing for a robot cell. It looked right in the catalog. It wasn't. Within weeks, the lines cracked from repeated flexing. The tubing cost about $640; the service call cost around $5,200, and that doesn't include the customer's lost production time.

The price difference between nylon and PU is small. The cost difference when the wrong material fails is large. My rule now: if it flexes more than a few thousand times a day, use polyurethane.

Scenario 3: High heat, chemicals, washdown, or food zones — Stop guessing

If the environment is unusual, neither PA nylon nor PU is an automatic choice. You need to know the exact temperature range, chemical compatibility, and any regulatory requirements. That's when I go straight to the Festo official website and use the Festo login to pull the datasheet for the exact part number.

This sounds basic, but I once approved an order for tubing that looked chemically resistant because the seller said 'heavy duty.' It wasn't rated for the coolant used next to the line. The datasheet was available the whole time. I just hadn't checked it.

I have mixed feelings about the term 'heavy-duty.' Part of me wants to just pick the strongest material and move on. Another part knows that overspecifying the wrong property can still miss the real risk—like heat, chemicals, or flex fatigue. The answer is to define the environment, not just the adjective.

The silicone question often appears in this scenario too. Silicone tubing can handle high temperatures, but it isn't resistant to every chemical, and its mechanical behavior is different from PA or PU. If someone tells you silicone is 'basically like plastic tubing,' that's a red flag.

How to tell which scenario you're in

The unhelpful answer is 'it depends.' The practical answer is to ask three questions:

  • Does this line move? If yes, how far and how often? A robot wrist that cycles ten hours a day creates a completely different load than a bundle that only moves during maintenance.
  • What is it touching? Cable ties, sharp sheet metal edges, cutting oil, washdown chemicals, UV light, heat sources. Each one adds a specific failure mode.
  • What happens if it fails? A tiny leak in a low-pressure pilot line is annoying. A rupture in a high-pressure line near a hot surface is dangerous.

If you're still between PA nylon and polyurethane, I lean toward the material that fails in the less catastrophic way. For most factories, that means polyurethane for anything with motion, PA nylon for anything static, and specialty materials only when the environment demands it.

Use the tools Festo gives you

If you don't have the technical data in front of you, stop guessing. The Festo official website has a support portal where you can search by part number, download CAD models, and compare materials. A Festo login also lets you check past orders and re-use correct specs instead of relying on memory.

The same logic applies to the rest of the system. When you order a Festo ISO cylinder, bore size and stroke length aren't enough—you also have to match the air supply. Undersized tubing can starve a properly sized cylinder. When you order a Festo air hose assembly, think about bend radius and fitting style, not just length. The Festo product range is huge, and that's only helpful if you use the catalog correctly.

The cheapest tubing is the one that still works in a year. The most expensive tubing is the one that fails on a Friday afternoon.

Look, I'm not saying one material is universally better. The most expensive tubing I ever bought wasn't the most expensive per foot—it was the one that didn't match the application. PA nylon and polyurethane both belong in a pneumatic system. The question is which part of the system you're working on.

If the line is fixed and protected, PA nylon is a solid default. If the line moves, polyurethane is usually worth the extra cost. If the environment is harsh, don't rely on a rule of thumb—check the datasheet on the Festo official website. It sounds boring, but it's how I stopped wasting money.