How to prevent cracking or splitting wood when fastening?
One way that used to be practiced back when carpenters actually hand nailed everything together, is to blunt the point of the nail you are about to drive by placing the nails head against the head of a nail previously driven, give the point a good whack, not hard enough to bend the nail you are blunting, just hard enough to adequately blunt the point. This flattens out the steel point and makes it actually rip its path through the wood as opposed to displacing the wood which can cause it to split.
When using a nail gun, I’ve seen many a carpenter, when nailing the end of a 2×4 to a perpendicular 2×4, by simply shooting a 3″ nail straight into the center of the perpendicular 2×4 causing the piece he is attaching to split at the end because his nail was so close the end. A simple solution to this is to back up from the end of the 2×4 being attached about 1 1/2″ and shoot the nail at an angle toward the center of the perpendicular 2×4 so that there is more wood at the end to help hold the 2×4 together. This idea can be used in any nailing or screwing application to help prevent splitting.
When screwing anything together that you definitely do not want to crack or split,..always drill a pilot hole. Many times it is a good idea to drill the pilot hole through the piece being attached and into the the piece you are attaching to, to the depth of the penetration of the screw, smaller than the diameter of the screw. Then drill a hole through the pilot hole you’ve just drilled in the piece you are attaching, that is larger in diameter than the screw. Then the screw will easily pass through the piece being attached but grip to piece you are attaching to, without displacing any of the wood enough to cause splitting or cracking. This will pretty much guarantee that you wont split or crack either piece.