Pink shared the story while playing "Burning Questions" with host Ellen DeGeneres, who asked the star to name the dumbest way she's ever hurt herself.
"Slashing tires," Pink responded. "It wasn't that long ago. It was Thanksgiving. Holidays are stressful."
"I got clean through the first one. He has a raised F250 and those tires are very thick, thank you very much," she said. "And the second one I lost a little steam and I hit the metal part and my hand just went straight down the knife."
The "What About Us" singer said she "didn't need any anesthesia" as she was treated for her injury.
"I got 13 stitches," she said. "But here's the thing, I didn't need any anesthesia. I couldn't feel a thing."
Pink and Hart married in January 2006 and are parents to two children, 7-year-old daughter Willow and 2-year-old son Jameson. The singer's kids gave her a homemade Grammy award following her loss Sunday.
Pink last released the album Beautiful Trauma in October 2017. She teased her new album and single "Walk Me Home" during an episode of The Ellen DeGeneres Show last week.