Buzz
Usually, a wrench can be used to loosen a bolt by turning the nut. However, if the bolt is rusted or stuck, alternative methods are necessary. If the hexagonal surfaces of the nut and bolt are undamaged, try using a propane torch to heat the bolt and loosen it. In most cases, a truly stuck bolt cannot be removed and will need to be cut off. Purchase all necessary tools from a hardware or home improvement store.
Steps
Loosen the Bolt with a Wrench or Pliers
Spray rust penetrant under the bolt head and around the nut. Rust penetrants like WD-40 will seep under the bolt head and nut, lubricating the threads. This method makes the bolt easier to remove, especially if rust is the cause of the sticking. Wait at least 20 minutes for the penetrant to work.
- Purchase rust penetrant from any hardware store. It is also available at major supermarkets.
Slide a hollow metal pipe over the wrench handle. Use a metal pipe at least 0.5 meters long. This extends the wrench handle by 0.5 meters, providing greater torque when removing the bolt.
- You can find hollow metal pipes at hardware or home improvement stores. Look for a pipe with an inner diameter of at least 20 mm.
- If needed, bring your wrench to the store to ensure the handle fits snugly into the pipe.
- However, using a hollow pipe to increase torque may risk breaking the wrench.
Attempt to loosen the bolt with the extended wrench. Fit the wrench head onto the stuck bolt, and hold the far end of the extended pipe. Use pliers with your other hand to grip the nut. Pull firmly on the pipe to loosen the bolt. If you're lucky, the rust penetrant may have weakened the bolt's resistance, allowing you to remove it.
- If holding both the wrench and pliers is too difficult, ask someone to assist with the pliers.
Use locking pliers if the bolt or nut is stripped. If the hexagonal edges of the bolt head are rounded or damaged, the wrench will slip. Locking pliers have teeth on the inner jaws, allowing them to grip stripped or rounded bolt heads securely.
- You can also slide a hollow metal pipe over the locking pliers' handle for extra leverage.
Apply Heat to Loosen the Bolt
Heat the bolt with a propane torch if other methods fail. If the extended wrench doesn’t work, use heat to loosen the bolt. Light the torch and hold the flame about 15 mm away from the bolt. Keep the flame on the bolt for about 15 seconds.
- The heat from the torch will cause the bolt to expand.
Use the torch flame to heat the nut for 15 seconds. After heating the bolt and allowing it to expand, shift the flame to the nut for another 15 seconds. Alternate between heating the bolt and nut for a total of 2 minutes. The unheated end of the bolt will contract, while the heated end expands, altering the bolt's shape.
- If you're lucky, the expansion and contraction will break the corrosion bonds.
Loosen the bolt with the extended wrench. Insert the wrench handle into the hollow metal pipe. Fit the wrench head onto the bolt and use pliers to grip the nut. Hold the nut steady and pull the wrench handle. Give it 4-5 strong pulls to see if the bolt moves.
- If the bolt doesn’t budge, heat it with the torch for another 10 minutes or try a different method.
Removing a Rusted Bolt
Use a wire brush to remove as much rust as possible. Scrub vigorously with a stiff-bristled wire brush to eliminate rust from the bolt (and nut). It’s challenging to remove a fully rusted bolt, so spend 4-5 minutes scrubbing to clear most of the rust.
- Hardware stores sell specialized wire brushes for rust removal.
Apply rust penetrant generously to the bolt threads. After scrubbing off most of the rust, spray rust penetrant on both ends of the bolt. Let the liquid seep into the threads beneath the bolt head for about 30 minutes. Effective rust-dissolving lubricants include Liquid Wrench, PB Blaster, and Royal Purple Maxfilm.
- Avoid using WD-40 for this purpose. While it’s a good lubricant, it’s less effective at breaking down heavy rust.
Strike the bolt head 6-12 times with a hammer. After applying lubricant to loosen the rusted bolt, use a hammer to strike the bolt head, creating vibrations that help dislodge it from its stuck position. The impact can also cause micro-fractures in the bolt, making it easier to turn.
- Vary the striking points to avoid hitting the same spot. Aim to strike each of the bolt's six sides at least once.
Use a long-handle wrench to remove a rusted bolt. The extended handle of the wrench provides greater torque compared to a standard short-handle wrench. Grip the very end of the wrench handle and pull with steady force. If applied correctly, the bolt should loosen.
- If you're unsure of the bolt size, try 3-4 different wrench sizes to find the best fit.
Destroy a stuck bolt
Purchase a bolt extractor that matches the bolt size. Measure the diameter of the threaded part of the bolt and buy an extractor slightly smaller (about 4 mm) to effectively remove the stuck bolt. Take the measurements to a hardware store to find the right-sized extractor.
- If you provide the bolt dimensions, the store staff can assist in finding the correct extractor.
Drill out the bolt using a bolt extractor. A bolt extractor is a long, threaded metal rod that attaches to a standard drill. Position the extractor tip at the center of the bolt and gently squeeze the drill trigger to bore into the bolt shaft, allowing the drill to remove the bolt from the inside.
- This method will destroy the bolt but is often the simplest solution.
Use a wrench to remove the drilled bolt. If the bolt doesn’t come loose during drilling, fit the wrench onto the drilled bolt head and turn it counterclockwise.
- If the bolt extractor damages the bolt and leaves fragments stuck in the hole, tap the bolt head and nut with a hammer to remove them.
Use a reciprocating saw to cut the bolt if other methods fail. If the bolt extractor can’t remove the bolt or if the bolt is too rusted for the extractor to drill into, cutting the bolt is the only option. Attach a saw blade to the reciprocating saw and position it against the stuck bolt shaft. Start the saw to cut through the bolt.
- Keep fingers and hands clear of the saw blade while cutting the bolt.
What you’ll need
Loosen the bolt with a wrench or pliers
- Rust penetrant spray
- Wrench
- Hollow metal rod
- Large pliers
- Vise grips
Apply heat to loosen the bolt
- Propane torch
- Wrench
- Hollow metal rod
- Large pliers
Remove a rusted bolt
- Wire brush
- Thread lubricant and rust dissolver
- Hammer
- Long-handle wrench
Destroy a stuck bolt
- Drill
- Bolt extractor
- Wrench
- Hammer (optional)
- Reciprocating saw
- Saw blade
Tips
- A metal engraving tool is effective for destroying the head of a stuck bolt.
- A bolt is a cylindrical metal rod with threading and a hexagonal head. A nut is a hexagonal metal ring that screws onto the threaded part of the bolt and can be tightened. When the nut is tightened, it clamps the material secured by the bolt.
- For very large stuck bolts, such as those with a diameter over 5 cm, use a pipe wrench. This tool generates significant torque, and its two jaws grip the bolt head tightly.
- For bolts with broken or flattened heads, a bolt extractor is essential.
Warnings
- Propane is highly flammable. Store propane in a cool place, away from open flames and other heat sources.
- Exercise caution when using a propane torch. The flame emits intense heat, so never direct it toward your face or hands.
