When you're piecing together a pneumatic or fluid-transfer system, the tubing line you pick has to fit the fittings and the flow. Two polyurethane options sit at opposite ends of the size spectrum: a compact black 1/8-inch OD air pipe and a wider blue 5/16-inch OD line. The black pipe lists at USD 9.75, while the blue line lists at USD 20.95. The decision comes down to how much outside diameter your connectors need and whether the extra price buys you the larger line you're after.
Quick verdict
Choose the black 1/8-inch OD PU line if your setup calls for a slim line at a lower listed price-it's rated to 363 psi and comes in a 10-meter coil. Choose the blue 5/16-inch OD PU line if you need a noticeably wider pipe and don't mind paying more for the larger cross-section.
Price and size comparison
| Product | Listed price | Price indicator | Outside diameter | Color | Material |
|---|---|---|---|---|---|
| 1/8-inch OD Black PU Air Tubing Pipe (10 m) | USD 9.75 | 0.13 in | Black | Polyurethane | |
| 5/16-inch OD Blue PU Air Hose Line | USD 20.95 | 0.31 in | Blue | Polyurethane |
The two lines are both polyurethane, but that's where the easy similarities end. The black pipe is noticeably slimmer than the blue line (0.13 in vs 0.31 in), making it a better candidate for tight routes. The blue line's wider OD also gives it a different visual footprint in a bundle of hoses.
Where each product wins
Black 1/8-inch OD line wins for compact routing and lower cost
The 1/8-inch diameter is the clear choice for tight spaces and fittings sized for narrow tubing. It also carries the lower listed price, so if you're buying a single coil for a small air-control project, this keeps the upfront cost down.
Blue 5/16-inch OD line wins for larger line size and visibility
The blue line is the bigger of the two, with a 0.31-inch outside diameter. That larger cross-section is what you want when your fittings are sized for 5/16-inch tubing. The blue hue also makes the line easy to spot in a multi-line assembly.
Product notes
1/8-inch OD Black PU Air Tubing Pipe (10 m)
This black PU pipe is a compact run at 10 meters (32.8 feet) and 1/8-inch outside diameter. It's rated to 363 psi, which gives you a solid working pressure figure to plan around. If you're feeding a small pneumatic control, an air brake line, or a water-transfer loop, that slim profile fits in tight channels. The catch is the size: if your connector or system is built for a larger 5/16-inch line, this 1/8-inch pipe won't match. At USD 9.75, it's the lower-priced option of the two, so it's easy on the wallet if the diameter fits.
5/16-inch OD Blue PU Air Hose Line
This blue line steps up to a 5/16-inch outside diameter, which makes it the larger companion in this head-to-head. That wider OD is the main reason to check the listing if your pneumatic tools or mechanical gas pipeline call for a beefier tube. The blue color gives you a quick way to distinguish it from other lines in a busy setup. It also carries the higher listed price at USD 20.95, so you're paying more for the larger cross-section. If your system needs a 1/8-inch line instead, this bigger hose is not the right fit.
Final choice by use case
If you need a slim, rated PU line for a compact pneumatic or air-brake application and you want to keep spending in check, the black 1/8-inch OD pipe at USD 9.75 is the pick. If your fittings and tools are built around a 5/16-inch outside diameter and you want a blue line that stands out in the run, the blue line at USD 20.95 is the one to put in your cart.
