Left-Hand Cut, Right-Hand Cut

Why are hay mowers right-hand cut and grain binders left-hand cut?

| August 1999

Somebody asked: "Why are mowers right-hand cut, while grain binders left-hand cut?" 

Cyrus McCormick, the younger son of the famous "Inventor of the Reaper," answered the question in his 1931 book, "Century of the Reaper," when he wrote: "Except for the accident of the reaper tradition, there is no reason why the cutter bar of a grain binder should extend to the left of the main wheel. The platform on all modern tractor-drawn apparatus projects naturally to the right, as does the bar of a mower; but since its inception, the standard binder has cut to the left."

McCormick's reaper, first tested in 1831, featured a left-hand cutter bar, along with a platform from which the cut grain was raked by hand. Apparently, there was no particular reason for this: it just was the way he chose to build the reaper. Obed Hussey also claimed credit for the first reaper, testing his machine in 1833. Most drawings of Hussey's machine reveal a left-hand cut, although I've seen one that appears to be the opposite. McCormick's machine prevailed, and most of the reapers built by other firms copied the left-hand cut setup.

During the Civil War, the Marsh Brothers improved the reaper by adding canvas aprons that carried the cut grain up over the drive wheel to a platform where two men hand-tied the grain into sheaves. About 1870, a wire tie device was added to a Marsh harvester, and hand-tying was no longer necessary. Farmers and millers didn't like the wire ties because pieces could break off and get into the flour or a cow's stomach. John Appleby patented a twine tying mechanism in 1875, and the self-tying binder, still in use by horse farmers, was born. These later improvements to the early reapers were built around the original left-hand cut concept that characterized binders until the end of production, so Mr. McCormick's comment about the "accident of tradition" seems to be accurate.

Mowers, on the other hand, took a different tack. William Ketchum patented the first successful hay mower in 1847, a single-wheel model with a rigid right-hand cutter bar. The improved mowers that came along later, two-wheel machines with hinged cutter bars, mostly all followed the right-hand cut pattern. Virtually all of the "self rake" reapers that were popular during the 1860s and 1870s were based on the mowers and were right-hand cut, as well.

During the "harvester wars" of the 1890s, as competition to sell binders became intense, McCormick suddenly changed all its binder production to right-hand cut. According to Cyrus Jr., the change was nothing more than an attempt to give the sales department a new feature to talk about and to draw attention to the McCormick machines. The change was soon quietly abandoned.