What Is It?

Lead pipe expander

This tool/device appears with regularity at mechanical hobbyists' meetings and at various other tool-focused events. It's always at the top of the "mystery-tool" list at these gatherings, and is almost never identified correctly.

The use of lead in the manufacture of pipes has been documented since Roman times. Lead sheets were formed into pipes or square channels and used to remove or supply water or waste products. Some of these early examples, which feature hammered joints, still exist today.

A hand pushing the arms of the pipe expander together to open the tapered head.

Until about 1900, many North American municipalities used lead pipes to supply domestic water. (These were gradually replaced with galvanized and black-steel pipes.) The National Building Code of Canada was amended to disallow the use of lead pipe and lead in solder in 1975. Canadian municipalities and provinces soon brought their codes into adherence. In 1988, under the Safe Drinking Water Act, the United States restricted the lead allowance in pipe and fittings to 8% or less. Solders and fluxes are required to have less than 0.2% lead content.

In 1998, another U.S. ban was put in place regarding the lead content in plumbing fixtures. Lead was also used to make the transition from a fixture to cast or clay pipe for waste products. Because of the flexibility and ease of shaping, lead sheet and pipe were used in p-traps and closet bends. A variety of bobbins and other unique tools were used to size and create the necessary forms for these connections. In 1895, John Anderson of Portland, Connecticut, devised a method of joining lead pipes that used a special fitting to expand the pipe, using a tapered piece inserted into the bore. Then a mechanical coupler was used to make the joint. This method allowed for straight runs of pipe to be assembled in sections longer than the existing manufactured pipe sections. His invention was patented (#535,236) on March 5, 1895.

A rear view of the pipe expander tool

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One year later, Mr. Anderson filed for another patent (#559,763) for a “tool for expanding ends of lead pipes”. This patent refers to the tool shown here. The description specifically mentions that this tool was to be used in conjunction with the previous earlier patent. Of particular note is the mechanical method of expanding the conical jaws in an even and controlled manner; this ensured the resulting expanded part retained some concentricity. It is also assumed that this tool was used in opening up an inlet in risers for joining dissimilar-sized pipes. The pipe expander has a unique mechanical advantage in that as the jaws are opened, they remain parallel; all that is required to create or enlarge a smaller opening in the lead medium is the insertion and full rotation. This method works due to lead’s extreme malleability.

Allegedly, Stanley Tools produced this tool; however, some examples have only the patent date imprinted on the tool, with no clear manufacturer’s name to be found. This pair is conspicuously marked with the patent date and the brand, “Wm Johnson Newark, N.J.”, which was a large, heavy-hardware retailer, circa 1905 to 1910.

D.S. Orr

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