Splitting the wood.
Screw acts as a wedge.
Board doesn't pull don't tight.
Major Diameter (The Outer Diameter): This is the distance from the top of the threads on one side to the top of the threads on the other.
Minor Diameter (The Root Diameter): This is the diameter of the solid metal "core" or shaft of the screw, not counting the threads.
This drill bit matches the major diameter.
This drill bit matches the minor diameter.
Here they are all together.
This is a countersink.
When drilling make sure to set to drilling.
We are attaching this board to another board.
This hole was drilled first for the clearance hole, and then countersunk.
This board is what we are attaching to.
This is an example of a pilot hole.
Adjust the torque down to a low number.
The torque setting allows the drill to slip so that it does not overtighten a screw.
Start low, and move higher as needed.
Line the screw up with the pilot hole.
Finished assembly.
Countersunk
Board is pulled tight and flush.