Attaching shelving

[Karl Fields]

My barn has 4'x2' galvanized studs on 4' centers. Plan tomorrow is adding some shelving at the 7' level, I am planning on going with heavy duty shelf brackets with 20" wide 3/4" plywood 8' long shelves.
Several concerns: One being will the plywood warp at 4' OC? Could add a 1x strip to mitigate this I guess.
Second issue is attaching the bracket to the stud. Drill it out and put a 5" bolt with washers? A little concern with buckling the metal.
Suggestions?

 

[VersionOne]

If you need it to carry a decent amount of weight, I would frame with 2x3's or 2x4's to span the 4' OC's.

I'd recommend using a self-tapping screw. Depending on the gauge of the stud, you up the diameter of the screw accordingly.