The McCormick 3121743R1 is a genuine OEM washer designed for various McCormick MC series tractors, including models MC100, MC105, MC110, MC115, MC120, MC130, MC135, MC80, MC90, and MC95. This essential component ensures proper fastening and load distribution in critical assemblies. With an inner diameter of 19.5 mm, an outer diameter of 32 mm, and a thickness of 1.5 mm, this washer provides reliable performance. It is also cross-referenced with equivalent part numbers for Case IH, New Holland, and Steyr machinery.