SAE J517 vs ISO 18752

What’s the difference and why it matters

Hydraulic hose standards can be a minefield if you don’t work with them every day. Two of the most common you’ll hear about are SAE J517 and ISO 18752. At first glance, they’re both doing the same job, making sure hydraulic hose is safe and reliable, but the way they go about it is very different.

Understanding those differences helps when you’re choosing the right hose or explaining to a customer why one option is better suited than another.

Construction vs Performance

The big divide comes down to this:

SAE J517 is construction-based. Each hose type is defined by how it’s built. For example, 100R1 is a single-wire braid, 100R2 is a two-wire braid, and 100R12/15 is a multi-spiral hose. Along with that, the standard sets requirements for things like working pressure, bend radius, and impulse cycles.
ISO 18752 takes a performance-based approach. Instead of telling you how the hose is built, it simply tells you the performance level it has to reach. Hose is grouped into constant pressure classes (350 bar, 280 bar, etc.) and impulse grades (A through D). A hose that meets Class 350, Grade D could be a spiral or a braid. The construction doesn’t matter; only the test result does.

Why the Difference Matters

Clarity with J517
Because J517 is construction-focused, you know exactly what you’re dealing with. This is handy for maintenance crews and anyone diagnosing failures in the field – you can look at the hose code and immediately know the reinforcement style and what to expect.
Simplification with 18752
ISO 18752 omits construction details and focuses only on performance. For equipment designers or global OEMs, this can make life easier – you just pick the pressure class that matches your system, and you’re done.
Adoption
J517 has been around for decades and is still the reference point for most of North America, as well as many hose manufacturers worldwide. ISO 18752 is newer but is gaining ground with companies that want to standardise across regions without worrying about wire counts or construction methods.

How to Spot Them

A hose marked SAE 100R2 or SAE 100R13 → that’s a J517 hose.
A hose marked ISO 18752 350-D → that’s an 18752 hose.

Which One Should You Use?

Both are solid standards, and neither is “wrong.” J517 gives you detail and transparency, which is useful for troubleshooting and compatibility. ISO 18752 gives you a cleaner, simplified way to specify hose by performance.

For many users, J517 still feels more familiar and easier to work with because it ties back to the construction details we’ve all learnt over the years. That said, ISO 18752 is becoming increasingly important in international projects and is worth keeping an eye on.