What is the minimum size screw recommended for fastening a 3/4" cabinet to a stud covered in 1/2" drywall?

To appropriately fasten a 3/4" thick cabinet to a stud that is covered with 1/2" drywall, it is essential to consider the combined thickness of the materials being penetrated by the screw. In this case, the total thickness includes both the drywall and the cabinet material.

The drywall is 1/2" thick and the cabinet is 3/4" thick, which sums to a total of 1 1/4" in thickness. To ensure a secure attachment, the screw must be long enough to penetrate through all these layers and also provide sufficient engagement in the stud. Typically, it is recommended that at least 1 inch of the screw penetrate into the stud to ensure a strong hold.

Therefore, when adding the 1 inch necessary for the stud penetration to the 1 1/4" total thickness, the minimum screw length needed becomes 2 1/4". This length provides the required coverage for both the cabinet and the drywall, along with the needed grip in the stud to ensure structural integrity and stability of the mounted cabinet.