Nail vs Screw Test 2006/11/01

I think I found the screws that Mike Holmes is using in his indoor drywall framing in basements with concrete slab floors and poured concrete walls. i.e. to screw vertical 2x4 studs to 2x4 top and bottom plates.

They're called Paulin High Performance Dura-Grip Construction Screws.
They're Yellow Zinc Dichromate Plated (not recommended for ACQ Treated Lumber).
They say "Outperforms nails in all projects where fasteners are required."
The examples are all framing with 2x material (e.g. 2x6's).

Imported by: H Paulin & Co. Limited, Toronto Canada M1L 4N3

http://www.hpaulin.com/

So I thought I'd try two tests:
a) how many bends to break?
b) Are the screws stronger (harder to bend)?

I bent them over with a sledge hammer.

Here's what they look like. The picture doesn't show it well, but there's a discoloration at the screw bend.

I straightened them with a pair of vice grips, and the screw snapped. I had assumed it would take a few bend/straighten cycles before the screw would snap. It snapped the first straighten.

The next thing I tried was on another new pair (screw, nail) was simply bending them by hand (no sledge hammer). I bent them to 45 degrees. It takes about the same amount of force to bend each. However, after one bend the screw is noticiably easier to bend then the nail, and the screw broke after bending it back the other 45 degree way (a 90 degree change). The nail broke at the 9th 90 degree bend.