How to Remove a Stuck Bolt

January 27, 2012

Running into a stuck bolt while doing an auto repair job can be one of the most frustrating things imaginable. However don’t get too discouraged; these things happen and there are plenty of ways to address the problem to get your project moving along again. Here are a couple of things you might want to try to remove that stubborn fastener.

Whack It

Sometimes all a stuck bolt needs is a couple of pings with a hammer to get it to start breaking loose. Simply take a metal hammer and give it a couple firm whacks square on the head (be careful not to deform the head of the bolt or damage other parts on the engine). Often the shock of being smacked with the hammer is all that is needed to break the adhesion inside the threads. Try this two or three times and see if that solves the problem.

Penetrating Oil

If that doesn’t work, the next step is to try flooding the bolt with a special penetrating oil. This type of product can be found at just about any auto parts or hardware store. It is formulated to work its way down into the threads and help to remove the adhesions that keep bolts stuck. You’re going to have to be patient though, penetrating oils are not an instant fix – they take time to work. A mixture of penetrating oil and a couple of whacks with a hammer will take care of the vast majority of stuck bolts. Apply the oil, let it soak in, whack it a couple of times and try again.

Impact Wrench / Breaker Bar

If it still won’t budge, you might consider trying an impact wrench. If you don’t have one that might mean that the car has to be moved to a shop that does or you’ll have to borrow one from somebody. Many shops will have a go at a stuck bolt for free or a minimal cost – as long as it’s relatively easy to access. The impact wrench works just like a hammer. It generates hundreds of tiny impacts a minute as it turns the bolt, which helps to break the bonds that are holding the bolt up. Another option is to use a breaker bar – a long extension handle that magnifies the force being applied to turn the bolt. However the danger with using a breaker bar is that you run the risk of snapping the head right off the bolt, which creates an even bigger headache.


The most stubborn bolts get the torch. To use a torch for loosening a fastener, you’re going to use the flame to heat up the area around the bolt – not the bolt itself. This method works by using the principle of expansion: when a material is heated, it expands. That means if the material that contains the bolt hole is heated up hotter than the bolt itself, it will expand away from the bolt allowing it to be loosened.  Just be careful that you don’t damage anything nearby by overheating it.