I built a cabinet (from a big box store plywood). I used 1/2" for tops and bottoms and 3/4" for the sides. This 16"dx22"hx30"w deep cabinet will be inset into the wall and fastened to the studs (so the back 12.5" will be hanging with no support). It will then be trimmed and painted so if a joint ever fails, it will be a big problem.
I used 1 1/4" screws, with pre-drilling and countersinking. But, tbh, it didn't feel like there was enough grab. Did I undersize the screws?
Or did I predrill it with too big a bit?