Hairpins made of fine metal , bronze , molded wood and other materials were already worn in ancient times by Assyrians and Egyptians to attach and hold on to the mostly artistically arranged hairstyles. As grave finds revealed, as early as 4000 years before Christ, Egyptians decorated their hair with hairpins and combs. Egyptian bronze hairpins of considerable length have been found. Antique hairpins were usually made of silver , copper , brass , ivory , shell , wood, or bone .
Grave finds show that hairpins were mostly luxury items for the Egyptians and Greeks , Etruscans and Romans because of their material value and workmanship. In Europe, the use of artistically decorated hairpins has been preserved through the Middle Ages and the Renaissance period up to the present day, hairpins in the shape of daggers , swords , halberds, among others, were also made here.
At present, hairpins and bobby pins can be roughly divided into two categories. While some are used to hold the hair in place, the others are only used to beautify and complete the hairstyle. In the latter case, the hairpins are often decorated with metal, pearls or rhinestones on the headpiece .
In the case of hairpins as well as hairpins and hair clips, a force acts perpendicularly on the hair axis. This creates a frictional connection which , in conjunction with the static friction that occurs, prevents the hair from sliding apart. While clamps and braces achieve this force through their own spring action , a hairpin must be inserted in such a way that forces act on them from different directions.
The term hairpin curve is derived from the tightly U-shaped curved shape of the hair clip.