For my CP clamps, what screws?

[crashwg]

I'm about ready to attach my CP clamps to the back side of my CP and I'm wondering what screws I should use.  The part that moves and basically does all the work will be screwed to the inside sides of the cab and will be pulling in a fasion that the only force on the screw will be sheer, but the pieces that those clamp on to will be screwed to the backside of the cp and have constant pull as if someone were trying to pull them out with a hammer.

I don't want to have any heads showing or anything like that so bolts aren't an option

So what should I use? They're being atached to a piece of 3/4" mdf which has a recess for them that is the thickness of the metal itself.  I'm thinking 1/2" screws.  My gut instinct would be to use a screw with the coarsest threads and the most of them.  What do you think?

[crashwg]

I guess since no one knows I'll have to go with my gut. 

[nostrebor]

The correct size drill bit and wood screws. Use the same length screw as the CP is thick, and the thickness of the clamp will prevent them from poking thru the top. This is how mine is put together. No worries as of yet!