I sure wish I had found this forum a few weeks ago. I have an American Deluxe Strat that needed some work because of fret buzz. I decided to take it to the local guitar store and decided to have new strings put on while the setup work was being done. I checked all over trying to determine the gauge of strings that were standard since I had never replaced a single string on this guitar. I couldn't find this information anywhere but found a site that said the gauge was 10-46. So I bought a set of 10-46 Super Bullets and told the store to put them on the guitar and set it up.

They did exactly as I asked them but when I picked up the guitar they told me that the Strats come with the 9-42 gauge as standard. However, they had installed the 10 gauge and setup the guitar accordingly as I had asked. I am at an intermediate level and really can't notice much of a difference. Does this matter? If I want to change back to 9-42 with the next set of strings does the setup have to be readjusted again? If I want to put 10-46 Flatwound strings on this guitar at some point can these simply replace the Super Bullets that are on there now or should this be done in the store?

The literature that came with the guitar (purchased new) didn't give any information about the standard gauge strings that were recommended for this model Fender. I found the information, after the fact, on this site by going to Product and then Specs.

It won't "hurt" your guitar to use any size string however over time if you're running really heavy strings, say 12's, you might need to adjust your truss rod. If you had it set up for 10's you can pretty easily switch back to 9's (although I don't know why anyone in the world would) or even up to 11's. Flatwounds shouldn't pose a problem either.

I have a strat set up for 12's and the nut has been modified (basically filed down) so that the the strings don't just sit on the top of the nut but actually seat correctly. I can still run 11's (which is as light as I ever go) and it works fine.

I guess what I'm trying to say is that you'll be good to go as long as you don't want to run super heavy strings... a set up suited for 10's will probably do you just fine and do no harm to your guitar.