Occasionally, we find a nail that was pounded from the interior casing, through the jamb, and into the weight pocket door, rendering the door inoperable. Rather than removing the nail, and risk marring the finish on the casing, we simply cut the nail, either with a hacksaw blade, or with a metal cutting blade in an oscillating multi-tool. Imperial brand blades seem to last many times longer than others. Even so, we use these blades with a delicate touch, alternating between various sections of the blade and only making brief contact. What is the enemy of sharpness? Heat.