A generally cylindrical cutting head for a weed cutting machine has blades that are exposed and lifted off of the head when an upper portion is rotated, with respect to a lower portion and/or a cap, without tools and without disassembly of the structure. A lock ensures that the upper portion does not open until desired, by a rigid plate or aim extending, in the locked position, through portions of both the upper portion and the lower portion, or through portions of both the upper portion and a cap portion. The lock plate/arm may extend into the cutting head from the top, bottom, or side. When pushed inward, the lock plate or arm moves to no longer reside in both upper and lower portions, or both upper and cap portions, to free the upper portion to rotate relative to the lower portion and cap.