How to Get Off a Rounded Nut

As described in the linked blog post there are several ways to remove a rounded nut. Here is a brief description of what a rounded nut is, how it becomes rounded and how you can remove one.

What is a Rounded Nut

A rounded nut, or the rounded head of a bolt, is a nut or bolt where the corner angles have been smoothed over, or rounded.  The effect of this deformation is that most tools will not be able to grip the fastener and will slip or spin when you try to remove the nut or bolt with the tool.

A rounded nut makes a repair job take much longer, a fifteen minute job can easily take an hour or more to complete.  Depending on how you attempt to remove the rounded nut, the job can also become significantly more difficult.

How a Nut Gets Rounded

A nut or bolt head will generally get rounded when you attempt to use the wrong tool for the job. For example, trying to use pliers when you should be using a wrench or socket; using the wrong size sockets; using 12 point sockets when the force required would indicate 6 point sockets would be the better choice. Using damaged tools also can increase the chance of rounding a nut.  If the nut is of poor quality or slightly rounded, it becomes easier to round further than a good fastner would be.

How to Remove a Rounded Nut

The best way to remove a rounded nut is to use tools designed for the job.  Some of these tools are nut and bolt extractors and nut splitters.  I have not tried them but Irwin tools makes a bolt extractor set and  a bolt extractor expansion set.  Other methods may be successful, but they may require more time and work.  Some other methods involve, heating, cutting, drilling, using pipe wrenches, welding a good nut to the bad one, pounding and knocking the nut in the direction it should go. This linked blog post shows how to remove a rounded nut as well as images of the nut, extractors and a description of some of the other methods used.