[1] Outlets for their products include independent tool-truck dealers, auto parts stores, and major internet vendors such as Sears and Amazon.com.

SK was founded as the Sherman-Klove Company, specializing in screw machine products, by Mason H. Sherman and Noah Grover Klove.

The company was founded in the early 20th century to supply munitions in World War I, and made mortar housings in a screw machine plant on Harrison Street in Chicago.

During the 1920s SK operated primarily as a contract company, making tools for other brands (including Craftsman).

SK invented the round-head ratchet wrench in 1933 and received a patent for it the following year,[4] which remains a mainstay of their, and every major competitor's product line today.