'W-Cut' fasteners are drill and screw in one
The "W-Cut" thread design from GRK Fasteners — available on all their screws — adds small teeth to the first few threads of a screw, making it possible to forgoe pre-drilling a hole entirely. Think of it as a tiny drill bit on the tip of each screw. These won't replace drywall anchors, probably the most common household drill-and-screw process, but for bigger construction projects they could save a lot of hassle, especially if you only have one driver, forcing you to keep switching bits.
Company Page [GRKFasteners.com via Core77]
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How is this different from yer basic self tapping screw wot's been readily available from countless manufacturers for decades?
From the company page, they "cut through" rather than "press aside" fibers in the wood.
But, hmm, when you drill you're removing wood -- sawdust comes out of the hole. Doesn't look like any wood is going to come out with these, and the displaced wood has to go somewhere... they don't look hollow. So it seems like there's still going to be plenty of wood "pressed aside".
Let's face it, these things are like any other screw, they self-tap into the materials they are designed to tap into. I can run them into a Canadian Hemlock 6x8 beam without pre-drilling, but try running a 3" one into a hundred-year-old block of American Black Walnut and you'll be reaching for that drill bit right quick.
Nice screws, appropriate to some jobs. Nothing to get all gaspy and stiff over.
--Charlie
Those pictures still look just like screws that I have been using for decades.
The Marketoids are at it again. The wedge shaped slice out of the screw at the bottom seems to result in a nice flat triangular surface on the leading edge of the thread, which would press against the wood as the screw is turned. Not sure how that would result in cutting of fibres.
As for the little notches further up the thread, the previous length of the thread (whats left of it) has already done the cutting, they serve no purpose.
But hey, I could be wrong. Double-blind (possibly literally, since you can see the thread notch) torque measured tests are now required to prove their claims. Whats that you say? A patent? Well then, by all means, forget science and go straight to the racking-in of the cash. :)
the idea of self drilling screws is old and today often applied to metal screws
http://www.mercateo.com/p/488BF-25530/DIN_7504_Bohrschrauben_Sechskantkopf_mit_Bund_K_verzinkt_weiss_5_5x38.html
they pre drill a hole into the metal and then the screw part follows on
the screws in the article do not really make sense, because there is no way the drill waste could get out of the hole, whereas se metal pendants cut throu an push the waste out at the back of the metal
How can a "W"-anything be a winning sales pitch just now?
These look a lot like SPAX screws, which do work. I imagine that if you can get them and don't mind keeping torx bit tips on hand, they are probably fine. The torx bits would discourage me. Just Phillips and square drive and their various sizes are enough for me.
In my line of work, as a sign installer for a company in New Orleans, we use those screws and the only way they work well is if you tap them into the surface you're drilling into first.
otherwise they act just like any old screw.