One of the sharpest swords ever made is the Damascus steel sword. Damascus steel is a type of steel characterized by its exceptional sharpness and strength. It originated in the Middle East and was commonly used during the medieval period. Damascus steel swords were known for their unique patterns and were highly prized for their cutting ability.

The exact process of forging Damascus steel was a closely guarded secret, and the technique was eventually lost over time. However, modern attempts have been made to recreate this type of steel using various methods. These modern reproductions, while not exact replicas of the original Damascus steel, can still exhibit exceptional sharpness.

It's worth noting that there are many other swords throughout history that were renowned for their sharpness, such as the Japanese katana, which had a curved, single-edged blade known for its cutting efficiency. However, the Damascus steel sword stands out as one of the most famous examples of a blade with exceptional sharpness.