Do Drywall Screws Rust Under Plaster? Will Drywall Screws Last Outside? Conclusion Do drywall screws rust? is a question you may have if you’re working on a DIY drywall project.

A phosphate coating on black drywall screws prevents them from rusting.
Sadly, just because these screws are rust-resistant doesn’t imply that rust won’t eventually grow on them.

Particularly if the coating strips during installation, this is the case. Drywall screws should only be used indoors because the risk of rust increases when they are used outdoors.

ARE DRYWALL SCREWS SURFACE RUSTY? Plaster may eventually cause drywall screws to corrode. The driver of drywall screws will occasionally remove the black phosphate coating from the screw heads before inserting them into studs or joists.

If this occurs, the plaster’s moisture could cause the screw to corrode.

DO DRYWALL SCREWS SURVIVE OUTDOORS? Outside, drywall screws will not hold up. Even varieties of screws promoted as rust-proof will eventually rust and cause corrosion when exposed to different weather conditions.

You should only use galvanized metal screws for outside work.
CONCLUSION The phosphate coating on drywall screws prevents rust, however when the screws are driven into studs, the coating occasionally chips off.
The screws may rust as a result of this.
It is more likely that drywall screws will corrode if you use them for outside home repair projects.
For outdoor application, galvanized wood screws are a much better choice.