In business by 1903, this firm made, and still makes, key seating millers.

Information Sources

• 1903 lathe patent granted to William L. Schellenbach and assigned to this firm. We have not found any mentions of this firm selling a lathe.
• 1903-11-05 The Iron Age: "A short time since W. L. Schellenbach, president of the National Machine Tool Company, Cincinnati, Ohio, designed a handy little too] for cutting internal keyseats, and the device has proved so satisfactory that the company now announce that they have completed a full line of the tools,..."
• 1905-10-05 The Iron Age: Harry Dolle and C. Naber, both of the National Machine Tool Company, were present at the October meeting of the Cincinnati Metal Trades Association. The December meeting was attended by Walter Dolle.
• 1906-04-12 (evidence that Schellenbach & Radcliffe is unrelated to this firm): "Schellenbach & Radcliffe, Cincinnati, Ohio, has been merged into the Schellenbach & Darling Tool Company. Of the new company, J. W. Darlng is president and treasurer; L. B. Gilbert, secretary and C. O. Schellenbach vice-president and general manager."
• 1911-01-05 The Iron Age: "William L. Schellenbach, formerly with the John B. Morris Foundry Company, Cincinnati, has resigned to accept a position as special mechanical engineer with the Lodge & Shipley Machine Tool Company."
• National Machine Tool of Cincinnati is an active business that makes key-seaters. Their website says, "Providing keyway solutions since 1903." Is is possible that this firm and the engine-lathe maker were two unrelated firms.