Answer by Ron Goden for 1/2" and 3/4" plywood cabinet - query about length of screws

Yes, you used the wrong screws and at the wrong angle. Sheetrock and or drywall screws are designed for there purpose. Which is NOT wood working screws. They are to brittle.Next time, do yourself a favor and get a pocket hole jig. They are self explanatory and very strong. This jig is designed to connect inside corners and hidden fasteners. They take the guesswork out of the equation.Like the gentleman before. You should be OK with your project.I am a professional finish carpenter with 30 years experience.