In 1996, Cornerstone and another private equity fund acquired Durand Equipment & Manufacturing Co. Durand is a leading manufacturer of aluminum concrete forms and related equipment and supplies. Founded in 1955 as a poured wall contractor, Durand switched to the concrete wall forming equipment and supply business in 1965 and began manufacturing its first aluminum wall forming system in 1976. In 1999, Durand was sold to a financial sponsor.