How do you repair cross-threaded bolts?

To repair a cross-threaded bolt, ensure the bolt's shank is free of damage, then use a die tool to repair the bolt. If the shank is damaged, it is best to replace the bolt, rather than attempt to repair it.

A die tool is a specialized tool that features the matching diameter and pitch of the threads on the bolt that needs to be repaired. Ensure the die tool matches the exact specifications of the bolt, or the bolt will be damaged beyond repair. To use the die tool:

1. Place the die on the bolt
Place the threaded and tapered opening of the die tool onto the bolt. Gently hand-turn the die tool onto the bolt, turning the same direction as the threads. Take care to ensure the die tool screws squarely on the shank.
2. Cut the threads
After the tool reaches the point of resistance, use a wrench or die handle to turn the die tool to reshape the threads. Alternate between clockwise and counterclockwise turns and let the metal chips between the grooves fall off. Apply a light oil to the threads to ease the process.
3. Apply the nut
Use the bolt with an undamaged and properly sized nut so the bolt is not damaged further.

A die tool is a great way to repair a cross-threaded bolt or screw, but it is also useful in removing damaged screws and bolts.