Valtteri Bottas’ troublesome right-front wheel will only be able to be removed once Mercedes gets its Formula 1 car back to its factory.
Bottas held second to Red Bull rival Max Verstappen at the Monaco Grand Prix but was left stranded during his sole planned stop when a wheel nut issue reared its head.
Mercedes could not remove the right-front tyre and Bottas was forced to retire from the race.
Explaining the issue, Mercedes technical director James Allison said: “If we don’t quite get the pit stop gun cleanly on the nut then it can chip away at the driving faces of the nut, we call it machining a nut.
“It’s like when you take a screwdriver and don’t get it squarely in the screw and you round off the face and then can’t take the screw out as you haven’t got the driving faces.
“If the gun starts spinning and chipping off the driving faces of the wheel nut then in quite short order, given the violence and power of the gun, you just machine the nut down to a place where there’s nothing left to grab a hold of.
“We didn’t get the wheel off. It’ll have to be ground off, get a Dremel out and painfully slice through the remnants of the wheel nut, we’ll do that back at the factory.”
Mercedes boss Toto Wolff described it as a “catastrophic failure” and outlined that the squad “needs to review the design and review the material of our wheelnut.
“The mechanics that operate the wheel nut need to do it in a way that you can’t machine it off.
“As a matter of fact, the mechanic that did that is one of the best and one of the fittest in terms of pit stop speed that the team has. Things always come together, it’s never someone’s fault. It’s always multifaceted.”