A hammer is a simple tool, used by most pre-industrial civilizations throughout the galaxy. It was used to drive solid objects into others or to forge metal into different shapes.
It was often a symbol of power on various worlds, such as Earth but the Ferengi viewed it as a sign of strong, sexual prowess. (TNG episode: "Birthright, Part I")
Commander Spock made an hypothetical point of one, using logic when he explained that he need not know whether or not gravity would cause it to drop when released. (TOS episode: "Court Martial")
- The ships named USS Mjolnir were named for Mjolnir, the hammer of the Norse thunder-god Thor.
In 2410, a hammer was displayed as trophy aboard a Hirogen Venatic-class battleship. It was seen by Seven of Nine and an Alpha Quadrant Alliance away team when they boarded the ship. (STO - The Delta Quadrant mission: "Revolution")