this is literally the core of all masonic ritual initiations. this is what they do to hiram abiff. he is struck in the head 3 times with a mallet/hammer.
As the temple is nearing completion, three fellowcraft masons from the workforce ambush him as he leaves the building, demanding the secrets of a master mason. Hiram is challenged by each in turn and, at each refusal to divulge the information, his assailant strikes him with a mason's tool (differing between jurisdictions). He is injured by the first two assailants, and struck dead by the last.[1]https://en.wikipedia.org/wiki/Hiram_Abiff