Steel Release: Impervious Armour

This technique allows the user to turn their body into jet-black steel. Hiruko states that blades do not affect him at all due to this ability, which is demonstrated when Sai's tantō snapped clean in half on impact.
== Trivia ==
* The portion converted into jet-black steel is similar in appearance and functionality to Kakuzu's Earth Spear technique, though Hiruko did not show the offensive usage.
== See Also ==
* Crystal Armour
* Earth Release: Earth Spear
* Earth Release: Hardening Technique
* Rock Armour
fr:Kôton - Corps d'Acier
pl:Uwolnienie Stali: Nieprzenikliwa Zbroja
pt-br:Estilo Aço: Armadura Impenetrável
ru:Стихия Стали: Непроницаемая Броня