Cyber-arm was a term used by the Eleventh Doctor to describe the arm parts of the Cyberman, as part of its Cyber-body. (TV: The Pandorica Opens) Attached to the Cyber-arm was the Cyber-hand. (PROSE: Plague of the Cybermen) Like the rest of the Cybermen, the arms were replaced by the original inhabitants of Mondas when they became weak. (TV: The Tenth Planet)
The Cyberman from Pete's World had concealable Cyber wrist blasters on their right arms, (TV: Army of Ghosts/Doomsday) while their hands could be used to transmit fatal electric shocks. (TV: Rise of the Cybermen/The Age of Steel) One Cyberman had both its head and left arm severed whilst guarding the Pandorica. Despite this, the separate parts were still active, with its Cyber-arm retaining its ability to fire its wrist blaster and transmit electricity. (TV: The Pandorica Opens)
The Cybermen that appeared in Hedgewick's World of Wonders had larger Cyber wrist blasters that were a permanent fixture. These Cybermen were able to separate their Cyber-hands from their Cyber-arms for the use of attacking and ambushing. (TV: Nightmare in Silver) The Cyber-Warriors and the CyberMasters also featured the same blasters on their right arms. (TV: Ascension of the Cybermen/The Timeless Children)
Ashad's human body was housed in a weathered Cyber-suit, (TV: The Haunting of Villa Diodati) with his right arm resembling those of the Cybermen associated with the Cyberiad, complete with an identical Cyber wrist blaster, (TV: Nightmare in Silver) but with a left arm resembling the Mondasian Cybermen of Mondas (TV: The Tenth Planet) and the Mondasian colony ship. (TV: World Enough and Time / The Doctor Falls)
In an alternate timeline shown to Jean-Luc Picard by the Eleventh Doctor, Cyber-Raxacoricofallapatorians possessed Cyber-arms which ended in clawed hands identical to regular Raxacoricofallapatorians. (COMIC: Assimilation²)