Tips to Avoid Wood-Splitting

[KregRep]

The number one suggestion is to make sure that you are using Kreg Screws.
Kreg screws have several features designed to limit, and even eliminate wood-splitting in your joints.
- The self-tapping tip drills the wood as it’s driven.
- The small diameter shank displaces less wood.
- The flat head doesn't wedge the wood apart when tightened down.
- The half-threaded shank eliminates binding.

Use Pan-Head Screws (SPS)
Our Pan-Head Screws have a smaller diameter that displaces less wood as it’s driven.

Use Fine-Thread in Hardwood
Coarse-threaded screws displace more wood with a more aggressive thread pattern.

Screw it In, Back it Out
By driving your screw half of the way in, back out, and then in again, you’ll reduce any excess wood in the hole.

Bee’s Wax
In extremely hard woods like Maple or Hickory, by applying some bee’s wax or other lubricant to the screw, you’ll reduce friction as the screw enters the workpiece.

Clamp, Clamp, Clamp
The primary benefit of clamping is to eliminate joint shift and reduce the need for sanding. Proper clamping also reduces workpiece movement, which can cause wood-splitting.

Test Pieces
Test your wood before you drill into it. Use a scrap piece that isn’t intended to be used on your final project.

Dry Wood Splits
It's important to understand what causes wood to split. In addition to certain species of wood being more prone to splitting, wood with low moisture is also more likely to split. If you live in a low-moisture location, your wood will be more prone to splitting and you’ll need to take extra precaution.

When All Else Fails, Pre-Drill
When you use your Kreg Jig®, pre-drilling your holes into the second workpiece isn’t required. However, in unique situations, with unique humidity levels, or uniquely split-prone wood, it might be your best bet! Warning: pre-drilling is not easy or recommended in almost any circumstance.

[Daniel Hanten II]

I see here that many people are talking about the screws and thickness of the stock which are all important, but i have found that the grain of the wood to be important as well.  If the grain of the wood is going with the short direction it seems to be more susceptable to splitting than if it goes with the long dimension.  Just another thing to look for when selecting stock from the shelf.

[John Magee]

Yes, that is a very good observation. Also remember if the stop collar is not set to the correct thickness of the wood, then you could be drilling the pockethole too deep allowing what should be the correct length skrew go out the face of the board and possibly splitting the board and for sure causing reason to cuss and extra sanding with your orbital sander!! And also always use the correct Kreg skrew for the thickness and hardness of the wood you are using. I always used 2 peices of scrap first to verify I had the right combination, and when I was sure of my settings I always use a little wood glue on every joint which not only strengthens the joint but also lubricates the skrew a little. It is easy to take a damp rag afterwards and wipe the joint clean before you start sanding. Hope this might help, I learned the hard way from trial and error. As far as the grain on the boards you are using, that would be hard to control if you were making faceframes for cabinets or furniture.

[Mark G]

My question is, when drilling your piece of wood, should the pilot of the drill bit protrude through the hole? In other words, should you see the small hole on the end of your board? And should that hole be dead center of the board as well?

[Steve Gronsky]

Mark ..... When drilling your pilot hole the drill bit should NOT come out the bottom.  However, when the screw is driven into it, it should be VERY CLOSE to dead center when it comes through.  Perhaps not EXACTLY dead center, but close to it.

[Ed Rarick]

I am building cabinets with very dry cherry for the face frames.  My rails and stiles are 1.5 inches and the stile is frequently splitting.  The collar is set correctly, I am using the recommended Kreg screw and I am not driving the screw in too tight.  In fact, the stile splits even when I hand tighten the screw just to the point of the joint becoming snug.  I even lube the screw and I back off the screw after driving it part way initially. It is DRY WOOD that causes the splitting.  I am even using only one screw in the center of the rail vs. 2.  The cherry is at 6% moisture and I am in Wisconsin where it is now winter.  The colder it is outside the greater the splitting problem.  When I start to make more face frames I will test size 6 screws vs. the standard size 7 and I will report back.

[Ed Rarick]

Why not just use a 1" screw rather than change the depth stop?

[Michael R. Turner]

For screw lube, I bought a toilet wax ring.  It is nearly the same thing as beeswax and provides more for less $.  Also, I have a 6" long 1/8" drill that I use to drill the screw hole all the way through the pocket board.  This way I eliminate the nub of wood that is pushed out by the screw that tends to push the joint apart.

[Lisa Zanni]

Great tips - I just want to add this

you can use a bar of soap if you don't have any bee's wax handy for lubricating screws and it

works very well.  I have used this for many years without any issues.

[Ed Rarick]

Use #6 fine thread screws rather than the standard #7 and the splitting should end.  It did for me with my cherry frames.

[Tony Lima Jr]

Thanks for the awesome tips! I have never heard of using bee's wax before, what a great idea.

[jim.zakany]

I agree with Ed. For hardwoods, I use Quickscrew #6 double auger pan heads and splitting has been eliminated.

[Don Hays]

Concerning the splitting.  I back off the colar on the step drill approximately 1/16 - 1/8" and I have never had an issue.