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How To Remove a Stripped Bolt

Stripped Bolt Head

Stripped bolt heads are the bane of every mechanic. They seem to always happen at the most inopportune time and on a bolt that is, of course, the toughest to get to. Stripped bolt heads mean a standard set of wrenches cannot grip the head to apply enough torque to break it free and turn it for removal. Luckily, for every stripped bolt out there, there are 1,001 ways mechanics have come up with to get them out. Here are some of the more realistic and useful ones.

Remember, always use a good cleaning agent to get any grease or oil off of the bolt head for a better grip and to use a penetrating oil to make turning the bolt easier.

The go-to option for many mechanics is to place a pair of vice grips tightly over the head of the bolt and use them to turn it. This will work for softer bolts (those made with softer metals) and smaller bolts. This will not usually work on large or hard steel bolts (such as grade 5 or 8, marked with three or five hash marks on the head respectively).

There are sockets and tools designed to grip a bolt head, even if it's been rounded off, by either creating grip points by "cutting" into the bolt head or by clamping down tightly and making a grip where a standard socket would not. For the most part, tools designed to grip stripped bolt heads usually work as advertised so long as the bolt fits the design criteria of the tool being used. Not every tool will work every time.

One thing you should never do is try to weld another item onto a bolt head. This rarely works and usually results only in making the bolt harder to get a-hold of and probably some busted knuckles. At worst, it can actually weld the bolt itself into its hold, possibly ruining the parts it's supposed to be holding in place.

The final tried and true method is very simple: soak the bolt, its threads, etc. in WD-40 or a similar penetrating agent and leave it overnight or for a few hours. Then try to remove it. On rusted and very stubborn bolts, whether stripped or not, this trick often works without a lot of fuss or gadgetry.