On 7/6/11 3:46 PM, Jack Stein wrote:

I drove all of them right down past the
countersink level with my impact driver. I did this 5 times with the
drywall screw to see if a hot screw would snap as Mike suggested, and it
was hot as hell, but didn't snap.


I'm guessing since it's already heat treated, heating up from friction
won't effect it.
Friction heat buildup on an un-heat treated screw will make it prone to
snapping.

ASAIK, the heat treating done to drywall screws makes them resistant to
stripping out at the heads and resistant to breaking from the friction
of being driven by powered drivers. The treatment also makes them very
brittle and not good for resisting heavy shear loads, like on holding up
decks or cabinets.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

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