Because she supposedly found three of the nails from Jesus' cross. Legend has it that one of the nails her son, Constantine I, place in his battle helmet for good luck and another was put in the bridle of his battle horse. My guess is that needles and nails were once made by the same craftspeople. She is also patron saint of troubled marriages, divorces...
Saint Helena is the patron saint of: against fire against thunder archeologists Birkirkara, Malta converts difficult marriages divorced people dyers empresses Helena, Montana, diocese of nail smiths needle makers
Saint Helena Augusta is the patron saint ofarchaeologists, divorced people, and empresses. Her son Constantine the great was an emperor. She was divorced to her husband and dug for the Lord's cross and found it. This was a great and holy woman who lived an extraordinary life.
There is no patron saint of costume makers.
The patron saint of boiler makers is St. Eligius.
The patron saints of clock makers are Saint Eligius and Saint Peter the Apostle.
The patron saint of casket makers is St. Stephen, deacon and martyr.
King Saint Louis IX is the patron saint of both soldiers and button makers.
There are patron saints of coin collectors but not of coin makers.
Claude de Columbiere is the patron saint of toy makers and turners as per the Patron Saint Index.
There is no patron saint of time. However, Saint Eligius and Saint Peter the Apostle are patron saints of clock makers.
There is no patron saint of glass. Saint Lucy of Syracuse is the patron saint of glass blowers, however, and she and Saint Luke are the patron saints of glass makers.
The Patron Saints Index states that Saint Colette and Saint Eligius are the patron saints of craftsmen.