|"If you open your mind, you will see that all the elements are one. Four parts of the same whole. Even metal is just a part of earth that has been purified and refined."|
|— Guru Pathik explaining metal's relation to earth to Avatar Aang.|
Metalbending is a specialized sub-skill of earthbending that allows an earthbender to ferrokinetically bend processed metal in a similar fashion to bending regular earth. Long regarded as physically impossible, the technique was invented by Toph Beifong to escape from a metal cage in which she was captured and transported by Xin Fu and Master Yu. At the same moment that Toph was trapped in the cage, Guru Pathik was giving Avatar Aang a lecture about chakras, and explained that metal is merely earth that has been purified and refined. Utilizing her unique ability to "see" using earthbending, Toph was able to perceive the trace amounts of "unpurified" crude earth still present in the metal, target it, and use it to bend the purified metal itself.
For thousands of years, earthbenders were not able to manipulate processed earth. During the Hundred Year War, the Fire Nation exploited this inability to detain captive earthbenders, such as when they forced earthbenders to work on a metallic prison rig in the middle of the ocean, and locked King Bumi in a suspended metal cage following the takeover of Omashu. Other nations used the same tactic, such as when Xin Fu and the Earth Rumble VI fighters captured Toph and Aang in metal cages and suspended them in the air, a situation impossible to escape from through the use of conventional earthbending.
During the spring of 100 AG, earthbending was changed forever when Toph Beifong was incarcerated in a metal cage by Xin Fu and her former teacher, Master Yu. While she was being transported back to Gaoling by her two captors, Toph desperately attempted to break out of the cage. However, Xin Fu commented that even if she was the best earthbender alive, it was still impossible to bend metal. At this point, Toph decided to test whether this was truly the case; realizing that metal was only a form of processed earth, she began to meditate in her prison until she was able to feel the trace amounts of earth in the metal. By utilizing these remaining fragments, Toph metalbent for the first time, tearing a hole in her cage and allowing her escape, while also imprisoning her captors inside the cage.
After the Hundred Year War, Toph established the Beifong Metalbending Academy to share the technique with others. By 170 AG, metalbending had become the primary form of earthbending used by Republic City's police force. The police use metal cables stored in cylindrical spool devices on their backs for various tasks, such as subduing criminals or for extra mobility around the city. The art also spread to earthbenders beyond the United Republic's borders, as some members of the Order of the White Lotus became proficient in the art. In addition, the city of Zaofu was constructed entirely by metalbending, an effort led by Toph's younger daughter, Suyin Beifong.
Toph's learning curve
Initially, Toph's metalbending seemed to be restricted to close-range manipulation. In almost all cases, she was standing close to or was in direct contact with the metal she intended to bend. She had "scrunched" or otherwise deformed sheets of metal, but had never caused it to freely reshape itself the way she had with earth, and was not known to have ever bent metal at a distance. However, when making direct contact with a prison's metal door, she was able to blast it off its hinges with such force that it ricocheted four times around the corridor beyond before coming to a rest.
Over time, Toph greatly increased the range of her metalbending and started to incorporate the technique in her fighting style, as demonstrated when she knocked several Fire Nation guards off a ship from several meters away and trapped a Dai Li agent in a metal column. She also developed the ability to "see" through metal, just as she could with regular earth.
By the time she, Sokka, and Suki set out to destroy Phoenix King Ozai's airship fleet, she controlled her metalbending more fluidly. She could easily tear a metal door off its hinges to fabricate herself a suit of armor and was able to manipulate the metal plating in the command bay of the airship from a short distance to pin her opponents against the walls. Toph was also able to metalbend the ship's floor upward to block a comet-charged fire blast just as a traditional earthbender would block attacks using a rock barrier. Her fine control over the art also allowed her to climb upside down along the metal ceiling of the airship while in her metal armor.
Toph later bent the rudder of an airship, causing it to spiral and collide with the other ships. When doing so, she took noticeably more time and concentration than if she had been required to do so with orthodox forms of earthbending.
A full year later, Toph was fully capable of bending metal she was not in contact with. For example, when a firebending teacher invaded her academy, she demonstrated her ability by effortlessly bending a metal weapon around his head that was a few feet away from her. She stated that as long as someone was close enough to see the metal, she could bend it. She demonstrated this by metalbending screws and bolts from a distance to unscrew the wheels of Fire Nation tanks. In her later life, she came to possess abilities such as being able to control cables from her armor, and being able to put on her armor, which appears to only be put on through metalbending.
Toph explained to Sokka how she found her first metalbending students; when she was close by each of them, her meteorite bracelet rumbled ever so slightly, due to the intense emotional state those particular people were in at the time. She realized that they were subconsciously metalbending the jewelry and thus figured that they had an aptitude for the art.
While teaching her first students, Toph forced them to remotely metalbend small coins rather than manipulate the metal via direct contact. Remote metalbending was favored over direct contact to break down the illusion of complete separation between bendable earth and purified metal at the beginning of the student's training.
Despite how widespread metalbending would become over the next 70 years, it is noted that only one out of a hundred earthbenders ever master the art, though metalbending master Suyin Beifong believes the only real limitation in learning the ability are the ones a person places on themselves. When Suyin first taught Korra metalbending, she got her to feel the fine pieces of earth inside a metal meteorite sculpture.
Metalbending in Republic City
In contemporary forms of metalbending, the Metalbending Police Force can bend metals without direct contact. An example of this advancement was shown when Lin Beifong unlocked Korra's handcuffs from across the interrogation room with just a flick of her hand. In another instance, Lin was fighting Equalist chi blockers on the roof of the Pro-bending Arena. She knocked two chi blockers off the roof by metalbending parts of the support rods.
Metalbending in Zaofu
The Metal Clan in Zaofu incorporates metalbending into numerous aspects of life. They have found ways to utilize their bending in the areas of fine arts, such as dancing and sculpting, recreation, with the invention of power disc, and architecture. In addition, the citizens of Zaofu employ a fluid variation of metalbending, as opposed to the more rigid and limited nature used in other parts of the Earth Kingdom.
Highly purified metals: Metalbending relies on bending the residue earth particles inside the metal. When the metal is highly purified, however, such as platinum, there are no or not enough particles left to bend, rendering the material impervious to the technique. Hiroshi Sato took advantage of this weakness to construct his mecha tanks out of platinum to counter any effective resistance from the Metalbending Police Force. Kuvira later did the same with her enormous mecha suit.
Metal connected to the bender's body: Similar to waterbenders, metalbenders often carry a source of metal with them to be able to bend anywhere. The Metalbending Police Force did this in the form of spools of metal cables connected to the metalbender's body. However, metal is a great conductor of electricity. Therefore, if the opponent of a metalbender is equipped with electrified weapons, like the Lieutenant with his electrified kali sticks, a jolt of electricity sent through the cables can stun the bender. Similarly, carrying around metal renders the bender vulnerable to magnets, as a large enough magnet can be used to capture the bender by dragging them away by the metal spools carried on their body.
- Metalbending was alluded to by Aang when he offhandedly stated, "What I'd give to be a metalbender," as he tried to carve a notch in the hull of the Fire Nation drill with waterbending.
- Avatar Korra is the first Avatar to use metalbending.
- Metalbending is prohibited during pro-bending matches.
- Metalbending forms are based on Chu Gar with modern military techniques mixed in.
- The limitations of metalbending are portrayed differently in the Avatar comics. In The Bridge, Toph can clearly be seen using metalbending without direct contact in order to tie up the firebenders opposing her, whereas in the series, she does not manage to do this until the finale. In The Promise, Toph also tries to teach her students metalbending remotely first rather than with direct contact, though this may be because of inherent differences between developing the talent and teaching it to others.