The Holy Nail is believed to be one of the nails with which Jesus was crucified. Supposedly they have been  recovered and  like other relics the Holy Nails have become an object of veneration among many Christians, especially among Roman Catholics and the Eastern Orthodox and have been pictured in paintings

  Very little reliance can be placed on the authenticity of the thirty or more holy nails which are still beung venerated, or which have been venerated until recent times, in such treasuries as Santa Croce in Rome, or those of Venice, Aachen, the Escurial, Nuremberg, Prague, etc.

      Probably the majority began by professing to be facsimiles which had touched or contained filings from some other nail whose reputed originals.claim was more ancient. Without conscious fraud on the part of anyone, it is very easy for imitations in this way to come in a very brief space of time to be.

      It is not clear whether Christ was crucified with three or with four nails, and the question has been long debated. The belief that three nails were used is called Triclavianism