Rough-in valve screws that will pass inspection

[sleepy hollow]

I cannot find any specific information online after extensive searching.  I have looked at the plumbing code and a variety of other sites.  No luck.  Here is the issue.

I passed my floor concealment plumbing inspection this week for my master bath remodel.  While looking over my new shower wet wall plumbing, the inspector indicated that the standard griprite gray deck screws may not be suitable for attaching the brass rough-in valves.  I was engaged in a variety of topics with him so never got back to ask for more specifics on this issue.  I figured I would just substitute brass screws and be done.  

I figured if I used non-ferrous screws I would be fine, but now I am wondering what exactly the code says.  I cannot find any reference to anything but the use of "corrosion resistant" screws in attaching toilet flanges to the subfloor.  I assumed he was referring to preventing galvanic corrosion.  My research there indicates stainless steel screws looks like they will work, though not sure I am reading that table correctly.  [Table found in this article:  https://www.monarchmetal.com/blog/galvan...-answered/]

Also chrome is good and apparently included in the coatings used by manufacturers.  Griprite has no info on their proprietary coatings, just a brand name.  

Does anyone know what the details are regarding any standards or other rules that can help guide me?  I'd rather stick with the installation I have than have to mess with it.  There are three valves, two shower head outlets and three body spray valves.  Brass screws are not cheap besides, an annoyance in the scheme of things to be sure.

So, any advice or additional education on this topic would be most appreciated.  

Thank you all.

[Snipe Hunter]

Probably not really a code issue. Things like that are usually installed "Per Manufacturer's Recommendations". If an inspector questions the installation, just show him the manufacturer's recommendations and he'll be fine. It might be something as simple as "non ferrous screws". He won't question brass or stainless steel screws. If you are concerned and it isn't in the provided instructions, call the manufacturer.

But deck screws are for decks. One of my pet peeves as a home inspector are deck screws and drywall screws used as universal fasteners.

[sleepy hollow]

Thanks for your response.  I am sure you are correct.  I'll go find some other screws and be done with it if I cannot get griprite to help.

[Cabinet Monkey]

I’m not aware of any Nat. Code requirement re: screws. May be a local thing for you.

I’ve always insisted on stainless or bronze for our projects.

The plumbers love it when I tell them that the drywall screws they put in are not acceptable and they must be replaced. And to go re- read their spec sheet/ contract.

Depending on how much grief they give me depends on whether I give them the screws or make them go to the store get them.