By 1915 Whisler Mfg. Co. of Gibson, IA, was manufacturing drill chucks, grindstone shafts and jointer heads. By 1918 the business had reorganized as the Whisler Manufacturing Co., with John Whisler still in charge; they were also manufacturing drill chucks. By 1925 the business had relocated 40 miles south to Ottumwa, and had added a line of complete safety-head jointers, though they continued to advertise square-head jointers for sale. The business survived until at least 1928 but we do not find evidence of their continuing into the 1930s, and they may not have survived the start of the Great Depression.

Information Sources

• December 1918 American Builder lists The Whisler Mfg. Co., makers of drill chucks, grindstones, power grindstone shafts, and jointer heads. Small ads in issues from that year have a murky image of a jointer head. The same ad appeared in 1918 issues of The American Blacksmith.
• 1925 State of Iowa, Directory of Manufacturing Establishments, page 95, under Ottumwa: "Whisler Mfg. Co. / Jointer heads, power grindstone shafts, drill chucks".
• 1928 edition of Engineers, Section 3 page 180: "Whisler Mfg. Co. (Cutter heads for jointers and planers, also complete jointers with round safety heads) Plant, Ottumwa, Ia. Owner, John Whisler".