Keller Manufacturing Co. dates back to 1924, when the first power hack saw was manufactured. At one point they were located at 1428 Cliff Road, Burnsville MN 55337, with another plant in Eau Claire, WI.
In 1978 they were Keller Manufacturing, Division of Sales Service Machine Tool Co., 3150 Mike Collins Drive, St. Paul.
The Keller business was sold around 2004 and is now known as Keller Industries, 828 Dunavant Road, Leeds AL 35094. They currently make updated versions of the original power hack saws.
As of 201? Keller Industries closed--support is no longer available.
Serial number data point: Machine #13580 was built in January 1975.
Advertisement from November 1954 "Popular Mechanics"
Information Sources
As of March 2012, the Keller website is no longer online.
Army Technical Manual for the Heavy Duty Model 3.
Army Technical Manual for the Heavy Duty Model 5.
In the mid-1950s, "Sales Service Machine Tool Co." of 2363 University Ave., St. Paul, MN, advertised in Popular Science and Popular Mechanics: the Jefferson 601 power hack saw, "F. O. B. Eau Claire, Wisc." Asking price was $71.50 with motor, $54 without. The saw's capacity was variably 3.5 inches square or 4 inches square.