• Share:
How to Loosen Stuck Bolts

Frozen, rusted bolts are a given in almost every auto or truck repair job. Instead of using anger and brute force, try one of these four proven techniques to work them loose.

By the DIY experts of The Family Handyman Magazine

Start with a rust penetrant

Rust penetrants contain a solvent to dissolve rust, a lubricant to reduce friction and a surface tension reducer to get deep penetration. “Home brews” like Coca-Cola, kerosene and mineral spirits don't have all those ingredients. Neither does WD-40 (it's a great lubricant, but it's not formulated as a rust penetrant). Those products simply don't work as well or as fast as actual rust penetrants (find penetrants like Liquid Wrench Penetrating Oil, Royal Purple Maxfilm and PB Blaster at home centers and auto parts stores).

Start by soaking all the bolts for at least 15 minutes before you attempt removal (Photo 1). If they still won't budge, move on to the “shocking” phase (Photo 2). You can smack the bolt heads with a hammer. But I get the best results with an air chisel and hammer bit (GRY No. CH117 hammer bit; from www.tooldiscounter.com).

I've also had good luck with an air chisel socket adapter (No. PH1050; from www.snapon.com). Slip an impact socket onto the adapter and pull the trigger (Photo 3).

If neither of those tricks works, heat and cool the bolt. The expansion and contraction will open cracks in the rust and allow the penetrant to work its magic. But before you apply heat, wash off all the rust penetrant (most penetrants are flammable). Next, remove any rubber or plastic parts that may be damaged by heat. Then heat the bolt head with a propane torch (Photo 4). Immediately shock the bolt with water spray (Photo 5). Once the bolt cools, reapply rust penetrant and try removing it.

Back to Top

Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

    • Hammer
    • Air compressor
    • Air hose
    • Socket/ratchet set
    • Impact Wench
    • Safety glasses
    • Soldering torch
    • Wrench set

You'll also need an air chisel, an air chisel hammer bit and an air chisel adapter.

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

    • Rust penetrant

Comments from DIY Community Members

No comments on the article have been posted yet. Be the first to add your comment!

You will be required to log in or create an account to post a comment.

closeX

Add Your Comment

How to Loosen Stuck Bolts

Please add your comment
closeX

Log in to My Account

Log in to enjoy membership benefits from The Family Handyman.

  • Forgot your password?
Don’t have an account yet?

Sign up today for FREE and become part of The Family Handyman community of DIYers.

Member benefits:

  • Get a FREE Traditional Bookcase Project Plan
  • Sign up for FREE DIY newsletters
  • Save projects to your project binder
  • Ask and answer questions in our DIY Forums
  • Share comments on DIY Projects and more!
Join Us Today
closeX

Report Abuse

Subject
Reasons for reporting post

Free OnSite Newsletter

Get timely DIY projects for your home and yard, plus a dream project for your wish list!

Follow Us