[1] In 1869, Fayette R. Plumb entered a partnership with Jonathan Yerkes, an established hammer manufacturer operating in the Frankford neighborhood of Philadelphia.

Shortly thereafter, a new facility was built in the Bridesburg neighborhood of that city, operating as Yerkes & Plumb.

The firm was one of the first in the United States to use cast steel to manufacture tools.

[1] The Plomb company began selling tools under the Proto name instead.

In 1981, Plumb was sold to Cooper Industries;[3] in 2010, the Cooper Hand Tools division was spun off into Apex Tool Group.