Repair Topics > Dealing with Rusted Fasteners > Rusted bolts and screws: 3 Professional tips to remove them

Rusted bolts and screws: 3 Professional tips to remove them

Use these professional tips to remove rusted bolts and screws

No matter which removal method you use to remove rusted bolts and screws, the job always starts by soaking the fastener in a rust penetrant. No, I didn’t say WD-40; that’s not a rust penetrant; it’s just a general-purpose lubricant. Instead of WD-40, I recommend PB Blaster or Liquid Wrench.

Pro Tip #1 Crack the rust before you apply rust penetrant

Rust penetrant helps dissolve some of the rust, and it wicks deep

Rust acts like glue, preventing the rust penetrrant from working. Vibration cracks the rust so the fluid can seep in

into the threads to provide lubrication. But if the penetrant can’t penetrate, it can’t work. So your first job is to break up the rust using vibration.

The best way to break the rust is with a hammer or an air chisel with a hammer bit (shown below). Your goal is to set up enough vibrations to crack the rust. Then soak it with rust penetrant and repeat the vibrations. That almost always works. In fact, if you use the air chisel hammer I show below, I’ve seen rusted bolts and screws and bolts vibrate themselves right out.

Pro Tip #2 Use heat to make the rusted bolt expand

SG 91125 Air Chisel Hammer

If rust penetrant and vibration don’t work, you’ll have to try heat. And this is another really misunderstood issue. Your goal is to shock the fastener, not destroy it. Everyone says to heat the bolt so it’s cherry red. They’re wrong. You do that, and you’ve destroyed the temper of the bolt, and you MUST replace it. Repeat after me: The goal is to shock the bolt, not destroy it. So heat the bolt until it’s hot. Then, shoot it with water to shock and cool it. The expansion and contraction will break up the rust. Keep spraying until it cools. They shoot it with rust penetrant again.

Pro Tip #3 Tighten the rusted bolts or screws instead of loosening them

Here’s another trick. Instead of always trying to loosen the bolt, try tightening it. If it moves at all, resoak it with penetrant and alternate between tightening and loosening. That’ll work the penetrant into the threads.