I'm in the process of building a table saw/router table extension. I've been using pocket hole joints made with a Kreg jig for the case so far. I was wondering if the pocket holes screws would be enough to hold the drawers and shelves without a dado. I'm using 3/4" construction ply for the sides and back and solid wood for the front. I'd like to have a couple of drawers at the bottom and an open space for the router and the lift. In everyone's experience are the pocket hole screws enough or should I add more support to the inside shelving. First post with the app. Might edit on the computer later if requested
Yes, pocket screws AND glue are enough to hold most drawer boxes together. We will often use them in a pinch for drawer boxes in the cabinet industry, and some shops will even use them regularly.
That being said, there are usually two weak spots in drawer construction, the bottom, and the drawer front.
For our typical drawer construction, we use 1/2" - 3/4" sides with a 1/4" bottom dadoed into all 4 sides. This makes construction and assembly simple, and results in a sturdy box. The drawer front is a separate part, applied to the front of the drawer box, usually using screws through the subfront of the box.
Building the box this way accomplishes a few things. First, your box itself has 4 sides, with the sub-front and back running between the drawer box sides. This hides any end grain from view. Also, you can put your pocket holes on the drawer box sub-front and back, where they will be completely out of view once in use.
Lastly, if you were to just screw the sides directly to the drawer fronts in a butt joint, those screws would be more likely to fail and pull out over time, and your drawer then has completely fallen apart. Having the sub-front, the screws holding the box together are perpendicular to the force from pulling the drawer open, and that force will be shear force, so that joint will be stronger.
Here is an interesting video on the strength of pocket hole joints: https://www.youtube.com/watch?v=apsH8eBfjVA