Internal Pipe Wrench

If you have ever done any plumbing in your home, and had to tighten a close coupled pipe nipple, you probably wondered how to grip it with a standard pipe wrench without damaging the threads.  So, you screw it into the mating fittings by hand and tighten them, assuming that the nipple will seal when you are finished.  Maybe it will, maybe it won't.  There is an easier way, but usually only the professional plumber has the correct tool to do the job.  


Today's tool was created to tighten or loosen a pipe nipple that has no external smooth surfaces except for pipe threads.  Of course, if you grip on the pipe threads with a standard pipe wrench or vise grips, the threads will be damaged and the nipple will become unusable.  So, an internal pipe wrench was designed to grip the inside of the pipe.  Turning the tool is accomplished by using a standard six point socket wrench or even a standard open end wrench.  As the tool is turned with the wrench, there are a number of small spline teeth on an eccentric ring designed to dig into the pipe interior as the tool is turned, either to tighten or loosen the pipe.  

The task of loosening and tightening small pipe nipples must have been a problem for many years, since there are a number of patents for internal pipe wrenches.  This particular wrench, made by Brasscraft and available at home centers or hardware stores, is most closely described by patent number 2455005, issued to Lee R. Hall of Tonasket, WA in 1948.   There have been several other designs patented since that time, but since this design is still in use over a half century later, it has definitely stood the test of time.


So, if you have a plumbing task in the future that involves short pipe nipples, save yourself some time and get a set of these internal pipe wrenches at your favorite tool store for $10-$12.