How to Loosen Rusty Bolts

Loosening a rusted bolt is a frustrating experience.

The right size wrench is key to loosening a rusty bolt.The right size wrench is key to loosening a rusty bolt.
Forcing the bolt or banging on it too hard often results in a broken bolt that requires even more work to remove. The job may be easier if you choose the right tool. An open-end wench or six-point box wrench are recommended by Popular Mechanics. A thick layer of rust and corrosion may make it difficult to find the wrench that fits perfectly. Experiment with both metric and standard sized tools until you find a wrench that fits snugly.

Scrub away as much rust as possible from both the bolt and its nut with a stiff wire brush. Tap the nut lightly on its flat sides with a hammer. Fit a wrench over the nut and turn slightly to the right before turning it to the left.

Saturate the bolt with a rust remover or lubricant such as an all-purpose household spray lubricant. Let the rust remover set for at least one hour then scrub the bolt and nut with the wire brush again. Tap the nut with a hammer and test for looseness. Repeat the lubricant application several times. If there is a thick buildup of corrosion on the assembly, let it soak on the rusted bolt overnight.

Put ice on a metal bolt to make the metal contract. Heat the nut with the flame from a lighter or small torch. Heat will make the nut expand. With a contracted bolt and an expanded nut, you should be able to loosen the bolt with a wrench.

Apply more leverage to a stubborn bolt by using a long handled ratchet or a breaker bar. Stop use of the ratchet if the tension goes slack or feels soft. This is a sign that you are stripping the bolt's threads.

Things You Will Need

  • Wire bristled brush
  • Hammer
  • Wrench
  • Household lubricant
  • Lighter
  • Long handled ratchet

Tips

  • Remember the saying "righty-tighty, lefty-loosey" when attempting to loosen a rusty bolt. Cranking your wrench to the right will only tighten the bolt further; however, a short turn to the right before turning left can help loosen a stuck bolt or screw.
  • It may take several applications of each step to free a very corroded bolt. Spray some lubricant on the bolt and take a break if you feel yourself getting frustrated.

Warning

  • Do not use a flame to heat a rusted nut if there is combustible material nearby, such as oil or gasoline in an automobile motor.