When you look down the throat of your disposal you can see the top of the rotor at the bottom of the cavity. On the top of that wheel there are two oblong shaped bars that are mounted with pins and are intended to rotate individually. Although those bars are commonly mistaken as cutters, they are not cutters, they are slingers.
Although you can not see it from the top, the rotor is about 3/4 of an inch thick and it has ridges machined around the outside surface like the ridges on the edge of a coin. The matching inside wall of the disposal body has a mating set of ridges and the actual grinding takes place between the ourter circumferance of the rotor and the inner circumferenace of the disposal body.
During normal operation as the rotor spins, the slingers throw the foodstuffs against the inner wall of the disposal where it is drawn down between the rotor and wall to grind it in the same manner as a mill wheel grinds grain.
The slingers are mounted to the rotor wheel by a metal pin on the inner end. They are intended to rotate but often the pins become corroded and they become stuck in one place. That will not have any appreciable effect on the overall performance of the disposal, and even if both slingers were pointed directly at each other, they are carefully designed for length so they cannot make contact.
If you are hearing a metalic grinding sound, there is still something caught in the actual grinding surface.
Begin by unplugging the disposal, then, using a flashlight, hold the rubber flappers back and look down to the bottom of the cavity. Examine the outer circumferance of the rotor and you will see a small gap about 1/8 of an inch between the outside edge of the rotor and the disposal body. That is the cutting area. If you do not see any obstruction in that groove, remove the drain connection from the side of the disposal body and look in the discharge hole, you will see the outer edge of the cutter wheel is about 3/4 inch thick.
On the bottom of the disposal under the motor you will see a hole in the center which is directly below the motor shaft. The is a recessed hex socket on the end of the motor shaft. You can insert a disposal wrench or a 1/4 inch allen wrench in that hole and manually rotate the motor shaft and cutter wheel. If the cutter wheel is free, the cutter and motor shaft should turn very easy. If you feel resistance, there si something lodged in the cutter groove. Continue turning and the obstruction should rotate around to the discharge port where you can pull it out with needle nose pliers. You will have to continue rotating the shaft and examining it both from the discharge port and from above until you discover what is caugth in the disposal.
Most often the problem will be a small metal object like a coin or a soda can pull tab.
Once you can rotate the motor shaft without resistance, reassemble the drain, plug the disposal in and it should be ready to go. You may be able to free up the slingers but if not, dont worry about them.