Purchase a penetrating oil at any hardware store. You might be able to find it at a large supermarket also.
You can find hollow metal bars at large hardware or home-improvement stores. Look for a bar that has a hollow inner diameter of at least 3⁄4 in (19 mm). If you like, bring your box-end wrench with you to the hardware store to make sure its handle fits inside of the metal bar you choose. Be aware that using a hollow bar to increase the torque of your wrench may damage or snap the wrench.
If it’s too awkward to hold both the wrench and pliers at once, ask a friend or family member to help you by holding the pliers.
You should be able to slip a hollow piece of metal over the end of vice-grip pliers just as you would over any other wrench.
The heat from the propane torch should cause the bolt to expand.
Ideally, the bolt’s expansion and contraction will break whatever corrosion holds it in place.
If the bolt still doesn’t loosen, heat it with the propane torch for another 10 minutes, or move on to another method.
Large hardware stores may sell wire brushes specifically designed for stripping rust.
Do not use WD-40 for this. While it’s an effective lubricant, it’s not effective at penetrating through layers of rust.
Vary the position of your hammer blows so they’re not all in 1 place. Hit near all 6 sides of the stuck bolt at least once.
If you’re not sure of the size of the bolt, try 3-4 different sizes of socket on the bolt until you find 1 that fits best.
If you have the bolt measurement, the sales staff can help you find a correctly sized extractor.
Although this will destroy the bolt, it should make it much easier to remove.
If the screw extractor shattered the bolt and pieces of the bolt are left inside the material that the bolt was screwed through, you may need to give the bolt head and nut a few blows with a hammer to remove them.
Keep your fingers and hands clear of the blade when cutting through a stuck bolt.
