Estwing hammers are the preferred tool of many carpenters and geologists. Ernest O Estwing was head engineer for the Remington Typewriter Company and then production manager for the Free Sewing Machine Company. He became frustrated with wooden handled tools breaking or with the head flying off the handle. The one-piece hammer with leather-washer handle was the result. The company began in 1922 on the second floor of Rockford Tool & Die. Incorporation was in 1923 by E O Estwing, John Nordholm, and Morris Nelson. The company is still in business, making an American tool using American steel.