The under cut should penetrate at least one third of the trunk diameter. Make the second cut 1 to 3 inches farther from the crotch than the first. The limb should split cleanly between the two cuts without tearing the bark on the trunk. You can then make the third cut at the crotch with less chance of the bark's tearing and leaving a jagged cut surface. The position of this cut is important to ensure rapid healing of the wound.
Many trees form ridges on the top and bottom of branches where they are attached to the trunk.
These are called shoulder rings. Pruning cuts should be made between the center ridges of these rings. The cut will not be flush or parallel to the trunk but will be out from it slightly, with the lower edge of the cut farther away from the trunk than the top. Such a cut will form a smaller wound than a flush cut, and callus tissue will form rapidly to cover the wound. Callus tissue should develop uniformly around the edge of the wound.