How does heating a bolt loosen it?

11 Answers. The answer is surprisingly simple: the bolt expands, but the nut expands more. What is happening here is good old thermal expansion: The bolt is heated and expands outwards, its radius increasing.

How do you loosen a stuck nut with heat?

Torch Your Stuck Bolt

Now heat the bolt and nut. Put the flame directly over the stuck part, or the part you can get to safely. Heat it for 30 seconds or so and it should free up easily. If it doesn’t, repeat the process to see if that helps.

Will Heat loosen a rusted bolt?

Another method to loosen a rusted nut and bolt is to use a heat torch on low or moderate heat. Heat will allow the rusted nuts and screws to expand so that they can be loosened.

Can a heat gun loosen bolts?

Heat up the bolt with your heat gun

Once you’ve spruced up the outside of the bolt, it’s time to address the hard-to-reach rust. This can be done indirectly by using heat. … Once the rust bond has broken, or at least weakened, you can begin loosening up the bolt.

How do you loosen tight bolts without tools?

What to Use if You Don’t Have a Wrench

  1. Duck tape. Duct tape is useful in almost any situation but you may be surprised to learn that you can use it to loosen bolts. …
  2. Two coins. Who would think that money can be used as a makeshift tool? …
  3. Zip-tie. …
  4. Another nut and bolt.
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Does metal expand when heated?

Metal expands when heated. Length, surface area and volume will increase with temperature. … The degree of thermal expansion varies with different types of metal. Thermal expansion occurs because heat increases the vibrations of the atoms in the metal.

Is MAP gas hot enough to loosen bolts?

A propane torch simply doesn’t get a fastener hot enough to help break the bond of corrosion. … You can look the composition of MAPP gas up on Wikipedia, but the take-away message is that it gets hotter than propane, but not as hot as an oxy-acetylene torch. It’s not going to melt a fastener, but it can get it glowing.

How do you harden bolts?

Quench & Temper Hardening Process

In the quench and temper hardening process, steel fasteners are first heated up to a temperature where their structure is converted into austenite and then quenched or rapidly cooled in water, oil or air to crystal structures that transform to martensite.

How much torque does it take to remove a bolt?

The bigger the bolt, the more torque you need to break it free. Typical homeowner quality 1/2 inch air wrench’s have about 250 -300 FT/LBS of torque. That is probably not enough for removing spring shackle bolts, especially if they are in rubber bushings.