I recently made a French cleat wall with 3.5” tall cleats with 2 1/2” construction screws drilled into the wall studs. I have no doubt the wall cleats are strong enough, however, my question is what do you guys use to secure your French cleat to the cabinet/object? I plan on making many shelving units for misc tools with my heaviest probably being around 20 lbs. would wood glue and brad nails suffice for the shelving cleat or should I use 1 1/4” construction screws? I am using 3/4” plywood for the shelving material as well.