Wood Screw Pull out in Plywood 1

[biggynugs]

I am a mechanical engineer playing structural engineer these days. I never really studied wood as an engineering material and am having a time trying to develop my methods for validating attachments into wood.
I need to hang a sign using a threaded rod with a 3/8 wood screw thread lagged into a piece of 3/4" plywood. The other side is a machine screw threaded into a piece of aluminum. I'm kind of stuck on putting a number to the pull out allowable of the wood screw.
Its an interior sign, no wind or water.

Any thoughts on where to go?

 

[MiketheEngineer]

How much does the sign weigh??

 

[biggynugs]

About 100lb. 2 supports, pure tension.
I am not necessarily worried about failure, but rather that I have to show a number that exceeds a failure criterion. Also, that I need to develop this skill for future analysis.

thanks for the response.

 

[CoryPad]

Here is a good place to start (see chapter 7):

http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/fplgtr113.htm

 

[biggynugs]

Holy cow that was awesome. What a great reference.

Thanks guys.