What length pocket hole screw for 3/4" stock?

Three-quarter-inch material takes a 1 1/4" pocket screw — coarse thread in plywood and softwood, fine in hardwood. Lengths for every thickness from 1/2" to 2".

3/4" stock takes a 1 1/4" pocket screw.

Coarse thread in plywood, MDF and softwood; fine thread in hardwood. The jig collar and the drill stop both set to 3/4" as well — the screw length is only right if the hole is drilled to match.

How that is worked out

  1. A pocket screw enters at a shallow angle and has to end up in the middle of the second piece — not short of it, and not out the far face.
  2. That fixes the length once the thickness is known, which is why the table below is a lookup rather than a calculation. It is the jig maker's table and every jig ships with a version of it.
  3. Thread choice is about the material, not the length: coarse threads hold in open, soft material, fine threads in dense hardwood that a coarse thread would split.

Pocket screw length by material thickness

Pocket screw length by material thickness
Material thicknessScrew lengthThread in plywood or softwoodThread in hardwood
1/2" – 5/8"1"coarsefine
5/8" – 7/8"1 1/4"coarsefine
7/8" – 1 1/4"1 1/2"coarsefine
1 1/4" – 1 3/4"2"coarsefine
1 3/4" – 2 1/4"2 1/2"coarsefine

Worth knowing

  • Set the jig collar and the drill stop to the material thickness, not to the screw. The screw length in the table assumes the hole was drilled where that thickness puts it.
  • In a joint between two different thicknesses, the hole is drilled in the thinner piece and the screw is chosen for that thickness.
  • Outdoors, or anywhere damp, the screw needs to be rated for it and the joint needs to be glued and sealed. A pocket hole is an open end-grain pocket pointing the wrong way, and it holds water.