Description 1 1/8"-12 Grade 8 Jam Nut for Rotary Cutter Blade. Will replace Bush Hog 252. This item is a suitable alternative for the following: 404-165242, 252, 252BH, N250, 735600, 753939, A-20900, A-7A4999, A20900, A7A4999, FJM118