In 1930, John Brush, Sr. and his brother-in-law, Willard Punnett, opened a small shop for the manufacture of safes at 545 West Avenue in Rochester, New York. The Brush-Punnett Company was an early pioneer in the stamping (metalworking) of steel safes. After a long and arduous startup period that spanned the Great Depression and World War II, The Brush-Punnett Company made some early successes by selling safes to Vassar College for its dormitories and steel skids to Eastman Kodak.

In 1943, after purchasing his sister and brother’s-in-law interest, John Brush Sr. became the sole owner of the company . It was Mr. Brush’s intent to pass the business onto his sons; John Jr., Richard, and Robert. John Brush Jr. joined the business in 1954 after serving active duty in the U.S. Army Air Corps, and graduating from St. Lawrence University (1950) and Harvard Business School. The company changed its name to the John D. Brush & Co. in 1955.

Brush & Co. moved into a new plant at 900 Linden Avenue (Rochester, NY) in 1968, with over 50,000 sq ft (5,000 m2). Then, in 1987, it began doing business under the name Sentry Group, in order to better identify the company with its trademark name safes – “Sentry”.

Sentry Group produces more fire-resistant chests, file cabinets, safes, security storage containers, and gun safes than any other company in the world and has won numerous awards for its product design and retail service. It was awarded “Vendor of the Year” from Lowe’s in 1999, Wal-Mart in 2001, and OfficeMax in 2002.

On November 13, 2007 at a press preview in New York City for the 2008 Consumer Electronics Show, Sentry Group announced its partnership with Maxtor Storage Solutions in developing the world’s first hard drives that are protected from fire and water, as well as computer crashes and theft. Among the new products is the SentrySafe Fire-Safe/Waterproof Hard Drive enclosure containing the Maxtor OneTouch 4 Mini hard drive in either an 80 or 160 gigabyte storage capacity.

Sentry maintains manufacturing facilities in Rochester, New York and Shanghai, China, and has sales offices located in the United Kingdom, Canada, and Japan. Today, members of the third generation, Doug and Jim Brush serve as Chairman and CEO.