Instead of exposing claw, Claw-in-hammer simply keeps its claw inside the frame of the head and still performs its duty and it also does functions of both a claw hammer and double-face hammer. Claw-in-hammer separates itself from other ordinary hammers in structural and safety aspects. A groove on the head was designed to fit the variety size of nails smallest nail up to the biggest.

This design was initiated in Taehun's undergraduate year. The sketch and the soft mock-up process suggested the modifications on styling and its structure. Structural defects and a curvature of a claw were mainly dealt in three dimensional sketches. Thoughts on the curvature of a claw and the minimum radius of nails’ heads helped apply into the creation. He also tried to find out potential discomforts that could be found in use.