Ordered my Collets.

[Cadillac STS]

Noticed you are in Florida. Do what you would do with other tools where you live. I agree with WD40.

 

[Bob Korves]

WD40 is a very poor preservative to prevent rust. I use ATF and also alternately use VPI paper. I live in the California central valley, where rust is only a minor problem if properly addressed. The real answer is to keep the relative humidity below 100% at all times around metals that can rust. It takes liquid water to make rust.

 

[mksj]

You can also use a coating/sealant system that is used on saws and also guns such as Top-Cote, my dad developed it and along with Bore-Cote years ago. There products were purchased by big box companies and renamed. I believe it is now called GlideCote by Bostik. There are other variants like Boeshield T-9. The Bore-Cote uses a combination of oils, waxes and carriers which drive out the moisture and put on a surface wax sealant if I recall. I typically use way oil on my collets, but clean the collets before I use them. I also but a small amount of way oil on the threads for my 5C and R8 collets when using them.

 

[Janderso]

Mine came in individually wrapped packages, plastic. I can’t believe they could rust if a light coat of spindle oil and returned to their container. I also live in Ca. Rust is an unknown out here. It rains but the humidity is low.
Good luck

 

[19E60]

I used to just spray them down with CLP, but didn't care for them remaining wet. I now use Hornady One Shot gun cleaner and lube on collets and many other things. It cleans and leaves a dry protective film, likely similar to the products mksj spoke of above. After use I simply spray down the collet, set it aside for a minute to dry, and return it to its storage. A quick shot of brakleen or contact cleaner down the bore of the collet and it's ready to go to work.

I live in California as well, but on the coast, in fact on an island surrounded by salt water; rust is very well known here and I have to be vigilant.