You can cut a pine tree into fence posts right after you cut it down. The younger wood near the top of the tree isn't suitable for fence posts, because the nails will fall out of the wood grain. Any part of the tree with a continual diameter of six inches is suitable for making fence posts. You can cut larger diameters in different ways to get more than one post out of the same log.
Cut a flat cut one-third of the way through the tree at its base. Make this cut on the leaning side of the tree.
Cut down toward the flat cut at a 70 to 90 degree angle until you create a notch in the tree.
Walk to the back of the tree and make a slight downward cut three inches above the apex of the notch until you hear and see the tree begin to fall.
Step back a few feet and allow the tree to fall to the ground.
Walk around the fallen tree and cut off all of the limbs sticking out. Cut the limbs off as close to the tree trunk as possible.
Remove the cut limbs from the work area.
Cut the main leader or trunk of the tree into fence post lengths. This length is usually 6 to 8 feet. Cut down through the tree to make these cuts. Roll the tree, if needed, to finish the cut.
Peel the bark off of each fence post using the sharp end of the hammer. The bark will strip off the wood once you get it going with the axe.
Lay two sleepers, on level ground, parallel to one another. Spread them about 5 feet apart.
Lay the fence posts horizontally across the sleepers and allow them to season for a few months before using them.
The round fence posts that are too big to be one posts can be halved or quartered to create smaller posts.
Wear safety glasses, earplugs, work boots, leather gloves, a hard hat and a long-sleeve shirt to protect yourself when using a chainsaw.