Kreg Jig Drill Depth Question...

[Derek Arita]

I was wondering, after drilling the pilot hole and countersink for the screws for pocket holes with the Kreg Jig, should the pilot hole go all the way thru or should it not be visible on the joint surface? This may make a difference with how well the mating pieces stay in place, while driving he screw.

[glenn bradley]

The pilot should not go through. As you state this will make a difference in the creation of joint-slip. Proper screw type and length are also critical to consistent success. The threads should not cross the joint once the screw is driven home. That is; the threads should all be in the target piece and the clean shaft should traverse the hole.

pocket-hole-screw.jpg

[Rick Potter]

Not to argue, but I would point out that on all the professional machines, like the Castle, they do go through. I realize Kreg recommends that they don't, and I do not claim to be an expert, just confused and curious.

I have had success with both....as long as you clamp very tight.
Rick Potter

[Lee Schierer]

Genuine Kreg screws have a cutting feature built into the threads so the screw drills its own hole as it is driven in. The screw shanks are smaller in diameter than the threaded areas so the screw will pull the joint tight when it is tightened. Therefore you do not need to drill the hole all the way through. If you are using the Kreg stepped bit, the pilot bit is too short to exit the end of the wood and still leave enough wood to provide a strong joint. You want the exit point of the screw to be in the center of the thickness.

[Matt Meiser]

I did some experimenting with this when I had my Foreman. Its more likely for the joint to slip if you drill all the way through because the pilot is much larger than the screw shank. You are also likely to get a small amount of blowout on the back side that must be cleaned off before joining the pieces.

I've found that running in the screws at a faster speed tends to slip less--I think the drilling point must work better. Then I end up switching to low and re-torquing.

[glenn bradley]

Not to argue, but I would point out that on all the professional machines, like the Castle, they do go through. I realize Kreg recommends that they don't, and I do not claim to be an expert, just confused and curious.

I have had success with both....as long as you clamp very tight.
Rick Potter

Yet another example of why the forum is so great. Thanks for the expanded information Rick. I should have noted that I was speaking from my experience which, as Rick noticed, has all been with Kreg consumer-type jigs. I wonder if for us home-shop or in-the-field type folks if the non-through hole has some benefit. . . meaning we don't have pro-type clamping jigs(?). Maybe a pilot tip of the stepped bit would be too long to be "home-shop tough" for hand held drilling and they get broken too easily(?). Maybe they're just keeping us amateurs from drilling a hole in our pinkies!?!