What Grade is Specified?

[Solarent]

A lot of equipment I come across calls for AW32, AW46 hydraulic fluid, with the occasional recommendation for AW22. In this case I know they are following the ISO rating system, which corresponds with the KV @ 40 C. But, I have also come across equipment designs which call for SAE grades and even dynamic viscosity measured by SUS.

What are the most common ways in your equipment that hydraulic oil is specified is it ISO, SAE or some other rating?

Personally I find the inconsistency across manufacturers difficult to deal with when matching hydraulic fluid to equipment needs, especially with newer "All Season" hydraulic oils which don't even follow the regular ISO grades...

 

[MolaKule]

They are inconsistent at times, although many seem to want to cover all bases.

The best we can do is use the viscosity cross-reference chart below:


http://www.bobistheoilguy.com/viscosity-charts/

 

[camelCase]

I think it more-so depends on the manufacturer and the engineers who designed it. Many will put simple SAE standards because it's what a lot of people quickly recognize. While ISO and SUS are more of the industrial standards with SUS being more US brands and ISO being more international - but just as much domestic as well.