How to Remove Stripped Bolts and Screws

One of the biggest frustrations when disassembling a piece of machinery or equipment for restoration, repair or even a service, is the dreaded seized or stripped bolt. Stuck hardware occurs when a bolt or nut gets corrosion between the threads, and they won’t budge. Many times, this leads to breaking the bolt off and having to drill and re-tap the hold or trying to remove it with a bolt extractor. We won’t even mention what happens when the drill, tap or extractor breaks off in the same hole! Here are some tips and tricks on how to get that screw out:

  • Use A Bit of Lubricant

  • If your bolt doesn't turn after moderate pressure, first spray on a product like PB Blaster or CRC's Freeze-Off. The former is representative of products that have a lubricant, which will work its way into very tight corroded surfaces. CRC Freeze-Off also has a penetrating lubricant, but adds the feature of contraction caused by the temperature differential. This product, if used properly, significantly chills or even freezes the bolt, causing it to contract, which will hopefully facilitate the entry of the penetrating lubricant and the separation of the corrosion. Usually, it takes a lot of spraying, but when it works, it is worth it.

  • Use Blunt Force

  • There are a few ways to do this:

    • One is to hit on the head of the bolt in the center with a chisel or punch.
    • Another is use an impact wrench/gun and hit it a few brief times in reverse and forward.

    Either of these methods work on the theory of freeing the corrosion bond between the threads by the vibration or the impact.

  • Heat It Up

  • When you heat and cool metal it expands and contracts. By heating the bolt, it expands due to the heat, and when it cools it will contract, thus breaking the corrosion between the threads.
  • A similar method is to heat the area around the bolt to make the hole it is threaded into expand and open a little so that the bolt fits a bit looser and can be threaded out.
  • Use of an impact wrench/gun helps when initially breaking it loose since the force from the hammering of the impact wrench breaks the corrosion apart as well.
  • Use penetrants like Kroil or CRC Freeze-Off to aid in the removal process.
  • Drill It Out

  • This is a last-ditch effort. It can also be used if the bolt has broken off flush with the surface. What you want to do is take a small drill bit and drill all the way through the bolt. This uses a bit of the chemistry a few of the other methods rely on. It heats the bolt by drilling it, and it also makes a hollow portion in the bolt, so it can contract more when you attempt to remove it.
  • I’ve had times when just drilling the bolt will allow the bolt to turn out quite easily.
  • Other times you may have to keep stepping up the size of the drill bit with a drill index until you are just a bit smaller than the diameter of the bolt. At this point, you may be able to carefully chisel or break the bolt apart in the hole. You can then extract the pieces and clean the threads back up with a tap set or a universal tap tool.

Marsh Fasteners

Marsh Fasteners has been supplying stainless steel fasteners for maritime use for over 2 decades. For the best in products, pricing, and service, contact us now!

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