Dante Autullo, 34, was in his workshop when a nail gun recoiled close to his head.
He was unaware a nail had been fired into his brain until he began feeling sick the next day and his fiancée convinced him to go to hospital.
Doctors at Advocate Christ Medical Centre in Oak Lawn, Illinois, who successfully removed the nail, told Autullo that it had come within millimetres of the area used for motor function.
His fiancée, Gail Glaenzer, told the AP: "He feels good. He moved all his limbs, he's talking normal, he remembers everything," she said. "It's amazing, a miracle."
She added that he'd jokingly told her to get TV cameras involved, declaring: "I'm one of those medical miracles."
Autullo was said to be in good spirits following the operation, during which part of his skull was removed and replaced with a titanium mesh to avoid contamination from the nail, hospital spokesman Mike Maggio said.
A similar incident occured in 2010 in California, when builder Victor Benavidez had an 8cm nail lodged just 1mm from his brain after the gun discharged when he was fixing a roof.