Door-head pins

Door-head pins (men zan) are wooden components utilized to secure the name plaque of a structure onto the horizontal middle beam of the structure's door-head. These architectural components serve both decorative and functional purposes. 

Door-head pins, which initially featured a square cross-section, can be traced back to the Han Dynasty (206 BC-AD 220). Over the subsequent millennia, the design evolved from square to diamond and rectangular, and later to hexagonal and octagonal. Throughout history, door-head pins have become increasingly ornate, with a decorative motif intricately carved on the front side.