Replacement castle nut for several Bush Hog Gearboxes, used to mount blade carrier to gearbox. Fits the following mowers: 1812 Flex Wing Cutter - Deck Assemblies, L.H. & R.H. Wings 1812 Flex Wing Cutter - Deck Assembly, Center 1812 Flex Wing Cutter - Gearbox Assembly, 540 RPM, Center Deck, L.H. & R.H. Wing - 00791028BH 2008 Rotary Cutter - DECK ASSEMBLY 2008 Rotary Cutter - GEARBOX ASSEMBLY, OUTBOARD - 50058056 2212 Flex Wing Cutter - Center Gearbox Assembly- 540 RPM 2212 Flex Wing Cutter - Left Hand Wing Gearbox Assembly - 540 RPM 2212 Flex Wing Cutter - Right Hand Wing Gearbox Assembly - 540 RPM 2212 Flex Wing Cutter - Gearbox Assembly Center - 540 RPM 2212 Flex Wing Cutter - Gearbox Assembly Left Hand Wing - 540 RPM 2212 Flex Wing Cutter - Gearbox Assembly, Right Hand Wing - 540 RPM 2308 Rotary Cutter (Multi Spindle) - Base Frame Assy 2308 2308 Rotary Cutter (Multi Spindle) - Gear Box Assy. Outboard BD 90 Rotary Cutter (OBSOLETE) - Drive Belts, Spindles & Blades BD 90 Rotary Cutter (OBSOLETE) - Gearbox Assembly P/N 70684 For All BD90 Models BD 90 Rotary Cutter (OBSOLETE) - Drive Belts, Spindles & Blades BD 90 Rotary Cutter (OBSOLETE) - Gearbox Assembly P/N 70684 For All BD90 Models BH10 Series (BH14, BH15, BH16, BH17) - BASE FRAME BH14 BH10 Series (BH14, BH15, BH16, BH17) - BASE FRAME BH15-2R BH10 Series (BH14, BH15, BH16, BH17) - BASE FRAME BH16-2R BH10 Series (BH14, BH15, BH16, BH17) - GEARBOX 00791027BH for BH16-2R BH10 Series (BH14, BH15, BH16, BH17) - GEARBOX 00791028BH for BH15-2R BH10 Series (BH14, BH15, BH16, BH17) - GEARBOX 71281 BH14-1R RF15 Flexwing Cutter SQ 420 - Squealer Rotary Cutter - Base Assembly SQ 420-2 SQ 420 - Squealer Rotary Cutter - Base Assembly SQ 420R-3 SQ 420 - Squealer Rotary Cutter - Gearbox (540 RPM) SQ 420-3 & SQ 480-3 P/N 71281 SQ 420 - Squealer Rotary Cutter - Gearbox Assembly P/N 70771 SQ 420 - Squealer Rotary Cutter - Base Assembly SQ 420-2 SQ 420 - Squealer Rotary Cutter - Base Assembly SQ 420R-3