Wood keeps splitting when using screws...

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biz_kid1's picture
Joined: 2011-02-12 21:43
Wood keeps splitting when using screws...
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Is my pre-drilled pilot hole too small?

I read a tip to dip the tip of the screw in soap before using, too. I don't know, but am willing to try!

"Stop screws from splitting wood as you are screwing them in. Dip the screw tip in soap before starting. You will find it tightens with ease." http://www.tipking.co.uk/tip/3511.html

Edited to add; found this, too: 

How to Prevent Wood Splitting With Screws

By Chris Deziel, eHow Contributor 

 updated: December 25, 2010

How to Prevent Wood Splitting With ScrewsthumbnailScrews will split dry, narrow or thin boards.

Using screws is an effective way to join wood as long as the wood doesn't split. If the wood is dry, the boards are narrow or you screw too close to the end, however, the displacement of the screw can force fibers apart, creating a less-than-perfect joint and possibly ruining the wood. This is an especially important issue in cabinetmaking and interior woodwork when you are working with kiln-dried boards that are fragile. You can create effective screw joints without splitting by taking a few precautions.



 Moderately Easy


things you'll need:

  • Drill
  • Drill bits
  • Paraffin wax
  • Carpenters' glue
  • Bolts and nuts
    • 1

      Mark the position of the screw and drill a pilot hole with a drill bit slightly smaller in diameter than the shank of the screw. Drill the hole completely through the wood on the top of the joint and partially through the wood on the bottom, leaving enough material at the end of the hole for the screw to bite into.

    • 2

      Avoid screwing within 1/2 inch of the end of a board. Even if you drill a pilot hole, the head of the screw may force the wood apart when you drive it into the surface.

    • 3

      Sink the head of the screw no more than 1/16 inch past the surface of the wood. If you want to sink the head deeper, countersink by drilling a hole to the depth you want to sink the head with a drill bit slightly larger than the head of the screw.

    • 4

      Roll a screw in paraffin wax until it is completely covered before driving it. The wax will lubricate the screw as it goes through the wood and prevent splitting.

    • 5

      Spread carpenters' glue between the boards you are screwing if the top board will experience lateral or outward stress. Examples of such a situation would be braces for cabinets or shelving. When the boards are held together with glue, there is less chance of their being pulled apart and splitting.

    • 6

      Use bolts instead of screws to attach hinges to thin pieces of wood. Drill a hole the size of the bolt shank, insert the bolt, and screw on a nut from the other side. The bolts will keep the hinges from pulling away from the wood and splitting it when the door that is attached to them is opened fully.


  • If wood splits while you are driving a screw, you can often remove the screw and repair the split with glue and clamps. After the glue dries, drill a pilot hole before driving another screw.

  • Splitting wood weakens structural integrity. If the joint will experience stress, repair the split or replace the wood rather than leaving the split as it is.

Read more: How to Prevent Wood Splitting With Screws | eHow.com http://www.ehow.com/how_6517096_drill-screw-wood.html

Tsu Dho Nimh's picture
Joined: 2010-09-05 20:30

Pilot hole may very well be too small.

Hold the drill bit and the screw next to each other, with the bit in front of the screw, hiding the screw.

Look at how much of the screw the drill bit is hiding, especially the threads.

  • If you can't see the threads, the bit is too big.
  • If all you see is the tips of the threads, the bit is too big.
  • If you can see the bottom of the thread groove on BOTH sides, the bit is too small.
  • If you can see the threads on both sides of the drill bit, and maybe the bottom of the thread groove on one side ... it's the right size.

That, and lubricating the screw with a bit of paraffin (wax used for canning for you who think it's a fuel used for lanterns) or hard soap, should make it easier.

biz_kid1's picture
Joined: 2011-02-12 21:43
Fantasic tip!

Thanks!  This has aided me tremendously!

claydowling's picture
Joined: 2011-01-26 17:28

With a wood screw you need to countersink the screw as well.  The angled base of the screw head splits the wood apart.  You can get a hand countersink at Harbor Freight, or the big box stores sell countersinks that can be chucked into a drill.  Of the two, I recommend the hand countersink because it's a bit faster.

If you don't countersink the holes you'll split the wood out every time.

biz_kid1's picture
Joined: 2011-02-12 21:43
Hand countersink might be faster...

But I did get a countersink kit for the drill - works AWESOMELY!  Thanks!  No split wood thus far! 

tncraftsman's picture
Joined: 2010-10-14 12:40
Pilot Hole Chart

Here is a reference chart for choosing the right pilot hole for the right screw size.

Wood Screw Pilot Hole Sizes


Mid-South Bunk Beds


edwin's picture
4x4 wood post splitting

hello, maybe you guru's can help this diy guy.

i am using 4x4 wood post that are 10' feet long.
as i drove the nails in the top and bottom of the 4x4 to add the brackets and connectors. the nails were to big and now the 4x4 post are starting to split.
how can i fix this?  the post are beginning to split from top to bottom, and some of the spits are pretty significant.  any help would be apprecitated
tncraftsman's picture
Joined: 2010-10-14 12:40
Pre-drilling the holes should

Pre-drilling the holes should prevent or minimize splitting.  The quality of wood could be a factor as well.  Another trick to prevent splitting with nails is to use a hammer to tap the pointed end of the nail to a blunt point. 

Something else to be careful of is where you drive the nail.  The closer you get to the endgrain the more prevalent splitting will be.

Good luck!

Mid-South Bunk Beds


claydowling's picture
Joined: 2011-01-26 17:28
Some wood splits

Posts that weren't properly dried will split, and your nail just makes a convenient starting point.  Some species, such as Douglas Fir, are naturally predisposed to splitting.  Which makes it great for working in some contexts, but terrible in others.