None of the writers of the Gospels focus on the details of being nailed to the cross because people already knew it was horrible. The soldiers used the cross as a tool for torture. They wanted victims to live for a while, sometimes for days.
Because the Sabbath would begin when the sun set, they sped up the crucifixion of Jesus (19:31). Jesus had been severely beaten with whips tipped with stone or metal, so his back was deeply cut, and he was bleeding heavily.