Can I use stainless steel cable ties on hot dip galvanised cable tray?

Only worry, I suggest, if you expect it to get wet. Certainly time to  failure will be measured in years and no worse than cable fixings of mild  steel band of the same thickness,
Mike

Hello Mike:

Based on stainless steel wire used in my kitchen sink draining unit, there seems to be a wide range of Stainless Steels being sold.

Some is very corrosion resistant and some is not.  

 I have seen the same thing with safety bars used in bathroom showers.

Peter Brooks

Palm Bay Florida 

The good cable ties are normally alloy 316 - which has molybdenum as the inhibitor and is actually pretty good, as well as being reasonable  to weld, tthough I agree there are some un-numbered stainless steels that barely qualify for the title.

The part that will corrode if wet will be the zinc, where the stainless band and the tray meet, but even once the zinc has corroded through, to rust the tray to failure  will take years.

Mike

Presumably you could use s/steel ties with a plastic sleeve or coating, so there'd be no direct metal-metal contact in normal service?

  - Andy.