Spark plugs that haven't been changed for a long time can become one with the cylinder head. Fortunately, it's possible to repair damaged threads instead of scrapping the head. (Photograph by Chris ...

Occasionally, spark plug threads are ruined by being stripped or burned out. When this happens, a product like these Phillips locking inserts comes in mighty handy. These neat threaded inserts can ...

If you need to screw something in but your hole is too big to fit, a bit of auto body filler will make that screw fit in like a dream. We've shown you how to fix stripped screw holes with toothpicks ...

We've all been there. You're tightening a bolt into a threaded hole and it's a bit harder than usual, and then the whole thing goes loose like the metal threads ...