ECN Forum Forums Code Related Discussion NEC & other Code issues sheet rock screws

Iwire...you're right, of course....here in the "High Desert" we don't have near the rust problems those of you in the salt belt do. :-)

How long would it take for a drywall screw to rust to the point of breaking in NE.? I can't imagine it would be a concern in my lifetime. I generally use #10 galv. screws but I can't see getting too excited about using drywall screws. My guess is the guy just wan't to find something to whine about.

I was looking through the forum and noticed this topic. I haven’t heard about the “no sheetrock screws” in a long time. Years ago an older electrician (a genius of an electrician at that) that I worked with on occasion told me not to use sheetrock screws because of the metal they were made with. The dissimilar metals between the screws and metal enclosures or boxes would make the area around the hole in the box and the screw rust prematurely and break. How long this would take I don’t know. I just know we couldn’t use sheetrock screws on his projects. Every now and then –such as this post- I hear of this issue and this was the only explanation I was given.

Mic.

It's called "galvanic reaction", and it causes molecules of one metal to migrate to the other, similar to how batteries work. Ever heard of a "sacrificial anode" in a water heater?

http://en.wikipedia.org/wiki/Screw#Tensile_strength

Edward