How to Drill Out a Stripped Screw or Broken Bolt

Pick the right method first

Not every stuck fastener needs a drill. Try the gentle fixes first: a wide rubber band or a little extra grip between the bit and the screw can pull out a lightly stripped head. If that fails, drilling is the reliable next step.

The method depends on what is left of the fastener. The table below matches the problem to the usual fix.

Gather your tools

Most of this kit is inexpensive and easy to find at a hardware store. Quality bits matter more than quantity, because a dull bit skates off hard steel and ruins the center point.

• A drill with a reverse switch and a low-speed setting
• Sharp drill bits, ideally cobalt or high-speed steel for metal
• Left-hand drill bits or a screw extractor set
• A center punch and a hammer
• Cutting oil or penetrating oil
• A clamp or vise to hold loose parts
• Safety glasses, work gloves and hearing protection

How to drill out a stripped screw

Work slowly. The goal is to remove the damaged head or the center of the screw without enlarging the hole in the surrounding material.

If you can still get any grip, try a left-hand bit first. As it bites, it can catch the screw and spin it out before you finish drilling.

• Remove the battery or unplug the drill, then fit the bit and check that it runs true.
• Tap a small dimple in the center of the screw with a center punch so the bit cannot wander.
• Start with a bit smaller than the screw shank. Run the drill at low speed in forward, with steady pressure and a drop of oil on metal.
• Drill straight down the center. If you only want the head off, stop once the head separates from the shank.
• Lift off the head, then remove the leftover shank with pliers or by turning it out with a screw extractor.
• Clean out the hole and check the threads before you drive in a new screw.

How to drill out a broken bolt

A broken bolt is harder because it is usually hardened steel and may be rusted in place. Soak it with penetrating oil and let it sit before you start. If part of the bolt is still sticking out, grip it with locking pliers and try turning it first.

If that does not work, center punch the bolt and drill a pilot hole straight down the middle. Keep the drill square to the surface. A tilted hole can damage the threads in the part you want to keep.

Next, choose one of two paths. A left-hand drill bit often grabs the broken bolt and backs it out as you drill in reverse. If it does not, switch to a screw extractor, tap it lightly into the pilot hole, and turn it counterclockwise with a wrench. Do not use the drill to power an extractor at high torque. Extractors are brittle and can snap, leaving a hardened piece that is very hard to drill through.

If the bolt will not move, drill it out gradually with larger bits until only a thin shell of the old thread remains. Pick out the shell, then clean the threads with a tap. Go up one bit size at a time, and stop before you reach the thread diameter.

How to drill out a rivet

Rivets are simpler. You are not trying to save the rivet. You only need to remove its head so the pieces come apart.

Use a bit about the same size as the rivet body. Center the bit on the dome, drill at low speed until the head pops free, and then tap the remaining shank out with a punch and hammer. If the rivet has a center pin, it often drops out as you drill. Clamp thin sheet metal first so it does not spin with the bit.

What to look for in a drill for this job

Extraction work rewards control more than raw power. You want a low speed range, a reverse switch and a clutch so you can stop before the bit grabs and twists. A two-speed drill gives you a slow gear for starting a pilot hole in steel and a fast gear for easier materials.

Our best drill comparison lists speed, torque settings, chuck size and weight side by side. For example, the DEWALT DCD771C2 has two speeds, 0 to 450 rpm and up to 1,500 rpm, and the AVID POWER CD316-20 tops out at 550 rpm. Both slower ranges suit careful starts, although the AVID has a smaller 3/8 in keyless chuck.

A 1/2 in chuck holds larger bits and grips round shanks more firmly, which helps with bigger extraction jobs. If you plan to do heavier repair work, check the chuck sizes and brushless motors on the drill comparison page before you choose. Weight also matters, because a lighter drill is easier to hold square for a straight pilot hole.

Safety notes

Metal chips can fly into your eyes, so wear safety glasses for every step. Wear hearing protection when drilling steel, because a bit that is binding can be loud.

Clamp loose parts. Never hold a small workpiece in your hand while drilling. Drilled metal and the bit get hot, so let them cool before you touch them. Take the battery off before you change bits.

Penetrating oil can be flammable. Keep it away from heat, flames and sparks, and do not heat a bolt with a torch that is near oil or fuel lines. Be careful with fasteners on gas appliances, brake parts or fuel systems. If a repair affects safety, ask a professional.

Frequently asked questions

Should I use hammer mode on a stuck bolt?

No. Hammer mode can shatter a hardened bolt or extractor and knock the bit off center. Use plain drill mode and a slow speed.

Can I use the same bit for stripped screws and broken bolts?

Often yes, but hardened bolts dull bits quickly. Use a sharp cobalt or high-speed steel bit for steel, and replace it once it stops cutting.

What if the drill bit wanders off center?

Stop and deepen the center punch mark. You can also start with a very small bit, then step up to larger bits, so the hole stays centered.

Why is my extractor spinning without gripping?

The pilot hole may be too large or the fastener too soft or rusted. Soak it in penetrating oil again, then try a left-hand bit or a slightly smaller extractor.

Will drilling damage the threads?

It can if the bit tilts or you go too large. Keep the drill square, increase bit size slowly, and clean the threads with a tap when you finish.