Founded 1909 by George M. Diehl in Peru, IN, but soon relocated to Wabash. An ad in a 1920 issue of The Wood-Worker gives the name as G. M. Diehl Machine Works. An ad in 1955-56 HWWDD gives the name as G. M. Diehl Machine Works, Inc.
Introduced the first straight-line ripsaw in 1913. Also made glue jointers, which planed both edges of random width stock; these machines were made obsolete by subsequent improvements in ripsaws by Diehl and others.
In 1999, Diehl merged with Wisconsin Automated Machinery Corporation. The DiehlMachines.com website has good information on buying a used Diehl machine.
- The 1980 book Planers, Matchers and Moulders in America, by Chandler W. Jones, says that Diehl started making molders in 1949, when they bought Vonnegut's molding machine line; machines were labeled "Diehl Vonnegut" for some time.
- Ad in 1955-56 Hitchcock's Wood Workers' Digest Directory. Machines pictured in the ad bear the "Diehl Vonnegut" name.