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How to Rethread a Bolt

How to Rethread a Bolt

One inevitable thing about bolts and screws is that you are going to need to rethread them with time. This is often as a result of their constant tightening and loosening, wear and tear and rusting.

If you are looking for ways on how to rethread a stud or bolt for decoration or any other application, here are the steps to take as well as the right set of tools you need.

What you need

To rethread a bolt, you will need:

  • A bolt thread repair tool/kit
  • Lubricating oil to reduce the friction caused by rusting
  • A vise to help secure the bolt in place when working on it
  • A wrench

The rethreading kit is equipped with things such as a metal die or file and a set of re-threading taps. These are usually made of stainless steel.


Equipped with the above tools you can then:

  • Start by applying the lubricating oil on the area around the bolt to loosen it up and make it easier to unscrew
  • Then use the wrench to steadily remove the bolt
  • Use the vise to hold the bolt firmly and securely
  • Now use any apparatus you choose from the rethreading kit (file or die) while ensuring it is kept perpendicular to the bolt
  • Clean the corresponding nut using a rethreading tap to remove the accumulated rust
  • Return back the bolt

While rethreading dies are used on the male component like the bolt, the taps are used for the internal threads.

How much does it cost to rethread a bolt hole?

The bolt hole is female and will need a tap to rethread. The cost of such a job will often depend on a number of factors such as the mechanic you hire or the job itself. Some rethreading can, however, be DIY and you will only need to have the right tools. This will save you some money.

How to make a bolt hole smaller

Sometimes you may find the bolt hole is larger and the bolt does not tighten. While getting a bolt that fits the size will work, another option can be to make the hole smaller. To do that you will need a metal filler compound or epoxy, then fill the bolt hole and give it time to dry before fitting the bolt.

Bolts have a wide range of use; from construction, manufacturing, home improvement, engineering, and many other applications. Knowing how to rethread damaged bolts will not only save you money but will also ensure they safely serve the purpose for a long time.