Invincible Armour, The (1977)

aka’s: Ying Zhao Tie Bu Shan/鷹爪鐵布衫

An assassin named Hu Lung (Lee Hoi-sang) murders a prominent Ming minister as part of a plot to overthrow the government. Official Chow Liu-fung (John Liu) is wrongly accused of the crime and escapes to find the killer and clear his name. Minister Chang (Hwang Jang-lee) sends his security chief Shen Yu (Tino Wong) to kill Chow. It turns out that Chang, an ambitious martial arts master, is behind the plot. He’s mastered Eagle Claw and the “Iron Armor” which makes his body impervious to blows or bladed weapons, except at one weak point. For a time, Chow stays with a brother and sister who teach him the Iron Finger, the only technique capable of defeating the Iron Armor. But the righteous Shen soon catches up with him and the two strike a deal to capture Hu Lung and discover the truth.