Stieff was the official maker of Pewter and Sterling for the Colonial Williamsburg Foundation, the Thomas Jefferson Foundation, The Smithsonian Institution, Old Sturbridge Village, and Old Newport.   Pewter became the major business of Stieff as sales of Sterling Silver waned since the 1960's.  Sterling Silver hollow ware was made at Stieff until 1999, but pewter became the star of the company in the 1970s and 1980s.

In 1979, The Stieff Company bought cross town rival, S. Kirk & Son.  As a part of the purchase agreement, the Stieff's agreed that the Kirk name would go first on the newly created company, creating Kirk-Stieff.  The Kirk factory in Baltimore and a pewter factory in Salisbury, MD were closed and operations consolidated into the Stieff factory.  The Stieff family continued to own Kirk-Stieff for 10 more years and the patterns of each company continued to be branded with the original companies' marks.  New patterns introduced by Kirk-Stieff were marked Kirk-Stieff.   In 1990, the Stieff family sold Kirk-Stieff in 1990 to Lenox.