Comment 1 for bug 717749

In my experience as a native American, the word "tongs" is, indeed plural, i.e. you never see "tong". However, each of these phrases are acceptable:
"Fire tongs are tools of the smelter."
"Fire tongs are a tool of the smelter."
"The tool of the smelter is fire tongs." ("is" refers to "the tool"-singular in this case).

Hope that clarifies things. :)