Capabilities of a Pocket Hole Machine
When drilling a screw hole in a stile, how close to the edge can you get? May 10, 2005
I am thinking of buying a pocket hole machine. If I drill a screw hole close to the edge of a stile, how close can I go, and will it split the stile? When screwing them together, do they screw flush or slip to make the two surfaces uneven so they need to be sanded flush?
I've gone as narrow as 1 1/4" rail/stiles and drilled two pocket holes in the ends. This puts the holes about 1/4" from the edge. The splitting issue only comes up if your machine setup is incorrect. The pocket hole should drill right to the end of the piece without protruding through the end. This leaves a pilot hole to within 1/16" from the end which will eliminate the split.
As far as the pieces being flush... you will need to clamp them somehow while screwing them together, either with a face clamp (which is just an adjustable vise grip type with a large pad on one end) or with a clamping table, which I highly recommend if you are doing many face frames.
Cut the pocket holes in the rails, running with the grain. They will screw into the stiles. The screw that is closest to the end of the stile will sometimes split it. You can pre-drill that stile, or just drop back to a little shorter, fine thread pocket screw for places prone to split.
Make sure you clamp facing prior to fastening with pocket screws. This assures a flush fit.
Set the driver torque properly and use good screws to minimize splitting. Over torque can cause the rails to split.
We have had a Porter Cable Pocket Borer for six years in a six man cabinet shop. I changed the pocket bit to 1/4 inch. It allows us to get more pocket screws in a confined space, the bits and routers last longer, and there is more wood remaining. The only drawback is you have to use a pocket screw with a 1/4" head. To prevent splitting and misalignment, we clamp the two components to a flat surface with welding clamps. If the clamp is placed where the screw will enter, there is no way it can split.