I realized you were quoting the code requirement but just wanted to give you my limited experience with plywood over steel studs.
One problem we had when sheathing the walls..... was that the threads would grab in the plywood (or OSB) & then the plywood would lift off the studs. It was a real pain.....looks like Tek now makes a screw for wood to steel studs that has a reaming wings that avoid the problem.
I think its call Ply-Tek or something like that
I would suggest using as large a head as readily available (esp for OSB which is not very strong at the screw hole level) plus the construction crew will like a screw that doesn't lift off.........you'll get better workmanship as well.
cheers
Bob
On 5/23/07, Jim Bessley <jbessley@gmail.com> wrote:
Bob,
Thanks. I was just reiterating the requirements from the code. Last night I was able to locate some dimensions on the internet. It appears that it is a #8 flat head screw. that is the minimum head diameter allowed. it appears that a #8 flat head can have up to a .332" diameter. close to the 3/8" you are talking about.
JimOn 5/23/07, Robert Kazanjy < rkazanjy@gmail.com> wrote:Jim-
That's a pretty small head diameter for a self driller / tapper for use in plywood
A number of years ago we did plywood shear wall (CoLA Shear Test Program) over steel studs & I recall that the screw heads were more like 3/8" or even larger.
I don't have the data readily available due to a crash ......... archived somewhere
Maybe the specs have been changed but it seems to me that a bigger head (3/8 or 7/16) would be better than .292" . A head dia of .292 seems pretty skimpy.
The screws were #8's or 10's
cheers
BobOn 5/22/07, Jim Bessley < jbessley@gmail.com > wrote:I am trying to design a shearwall using the 2003 IBC for plywood sheathing over light gage metal studs. the code says that the screws should be self drilling and tapping screws with a .292" head diameter. I can't find the screw size that correlates to this head diameter. Can anybody out there help me.
thanks,
Jim Bessley