McCormick-Deering W series tractors

In contrast to the letter series row-crop tractors, which were intended to straddle one or more rows in a field with high clearances and adjustable axles, the W tractors had fixed wheel widths and a generally lower profile with smaller rear wheels and wide front axles, since they were meant for plowing, orchards, wheatfields and other applications that did not require the row-crop features. The McCormick-Deering W series was closely aligned with the International Harvester industrial tractor series. Industrial tractors had different gearing and a foot-operated throttle. The W series retained the same Raymond Loewy styling as the letter series tractors.[1]

The McCormick-Deering W-4 was based on the Farmall H and used the same International Harvester C152 152-cubic-inch (2,490-cubic-centimetre) displacement gasoline engine, with options for kerosene and distillate fuels. A five-speed sliding-gear transmission was standard, with fifth gear disabled on tractors that were delivered with steel wheels. Overall weight for single rear wheel tractors was about 3,800 pounds (1,700 kg). The W-4 was first produced in 1940.[2][3]

The industrial version was the International Harvester I-4. A McCormick-Deering O-4 was intended for vineyards and orchards, and had fenders and fairings designed to avoid snags on branches, with the exhaust routed underneath instead of overhead.[4] The OS-4 version only had the underslung exhaust, without the sheet metal guards.[5]

In 1953 the Super W-4 was introduced, with an International C164 engine with 164-cubic-inch (2,690-cubic-centimetre) displacement. A total of 35,868 W-4s of all versions was produced from 1940 to 1954.[2][6]

The McCormick-Deering W-6 was the W-series version of the Farmall M, using the M's C248 engine, again in gasoline, distillate or kerosene versions. The remainder of the W-6 drivetrain was similar to the W-4's, but the tractor was heavier at 4,800 pounds (2,200 kg). A diesel version was also offered, the WD-6. The WD-6 was rated for three or four plows. As with the W-4, versions were made in W-6, WD-6, O-6, I-6 and ID-6 models.[8] OS-6 and ODS-6 models omitted the sheet metal guards, but kept the rearranged exhausts.

The immediate predecessor to the W-6 was the International W-30, a version of the Farmall F-30, which had a wide front axle in comparison to the F-30's narrowly-space front wheels. The W-30 was produced from 1932 to 1940.[9]

Super versions were introduced in 1952, using an IH C264 engine. A Super W6-TA and WD6-TA line was produced in 1954, with torque amplifier transmissions. Production of all models of the W-6 totaled 56,482 from 1940 to 1954.[10][11] Australian models, designated AW-6, were produced from 1949 to 1953.[12] The AW-7 followed in Australia, as a counterpart to the Farmall 400, from 1957 to 1960.[13][14][15][16]

Rear view of a W-D 9, showing the low profile compared to row-crop tractors

The McCormick-Deering W-9 departed from the letter series parallel, using much more powerful engines from International Harvester's crawler tractors, and heavier drivetrains. The W-9 was first produced in 1940 with the C335 engine used in the T-9 crawler. Running on gasoline, distillate or kerosene, it produced 44 horsepower (33 kW). Operating weight was over 10,000 pounds (4,500 kg). A WD-9 diesel version of the same displacement was available. Industrial tractors were the International I-9 and ID-9, and a special steel-wheeled rice field variant was the WR-9 and WDR-9. The Super W-9/WD-9 was produced in 1953 with greater torque.[17][18][19]

The predecessor to the W-9 was the McCormick-Deering W-40, a bigger version of the International W-30 with a six-cylinder engine, which was itself a wide-front-axle version of the Farmall F-30. A diesel-engine version was available, the WD-40. Both tractors were also sold as industrial tractors, the I-30 and ID-30. Production ran from 1934 to 1940.[20]

International Harvester 600

International 650 tractor

The International Harvester 600 was a re-badged version of the Super W-9, with few changes, following the Farmall 100/200/300/400 numbering scheme, and dropping McCormick-Deering branding in favor of "International." 1,516 600s were produced in 1956 and 1957.[21][22] The International Harvester 650 was the successor to the 600, with a few more changes. 4,933 650s were produced in 1956 and 1957.[21][23] The 650 was succeeded by the restyled International Harvester 660 in 1959.[24]