Bolts that have been in place for a long time often become so rusted they cannot easily be loosened with a wrench or socket. Exposure to moisture makes them even rustier. Trying to force a bolt will likely just damage the head of the bolt, making it even harder to remove. Trying to force off a rusted bolt can also injure a worker's hands, especially if the socket or wrench slips. There are, however, effective and safe ways of loosening tight and rusted bolts.
Spray a commercial rust-removing solution or lubricant on and around the bolt, trying to cover as much of the bolt as possible. Wait a few minutes. Loosen the bolt, if possible, with a wrench.
Use a propane torch to heat the top of the bolt if it remains stuck. Before applay a flame, though, wipe up or dry off with a rag any remaining rust-removing solution or penetrating oil around the bolt. Flames and petroleum-based solvents aren't a good combination. Heating the top will cause the entire bolt to expand. It should take about a minute.
Place a wrench back on top of the bolt and turn counterclockwise. If the bolt becomes too rounded for the wrench to fit properly, tighten a pair of lock pliers onto the head of the bolt. Once it is locked into place, push or pull the pliers counterclockwise to loosen the bolt, using as much force as necessary. If the bolt still will not turn, tap the pliers with a hammer counterclockwise until it loosens.
Put a socket onto the head of the bolt if it still will not loosen and then place a short piece of pipe over the socket handle. This piece of pipe is often called either a buster bar or a cheater bar. Grab hold of the buster bar and push or pull counterclockwise until the bolt loosens. Do not use too much force or the socket might break.
Cut off the top of the bolt with a hacksaw if it still will not loosen. A cold chisel or reciprocating saw may be used instead. Another way to break the bolt is to use a nut splitter. It will break the nut without damaging the threads of the bolt.
Remove the rest of the bolt with a screw extractor. Take the drill bit that came with the screw extractor and place it in a drill. Then drill a hole through the centre of the bolt. Place the screw extractor in the recently drilled hole and turn counterclockwise until the bolt is removed.