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Implements & AttachmentsRotary Cutter Buying Guide
A rotary cutter, or bush hog style mower, handles pasture, ditches and brush that would wreck a finish mower. A little homework before buying keeps the cutter and the tractor in a good match.
Key points
- Match the cutter to your tractor's PTO speed, lift and weight using the manual.
- Compare the gearbox, deck, blades and shielding, not just the price.
- Keep every guard in place, and clear debris before mowing.
- Inspect used cutters for cracks, bent spindles and missing shields.
What does a rotary cutter do best?
A rotary cutter has one or more blades spinning under a steel deck, driven from the tractor PTO. It cuts tall grass, weeds, light brush and overgrown pasture. It does not give a manicured finish, and it is not a hay mower. It shreds material and leaves it on the ground.
For a 30-acre hay field that needs a late-season clip of weeds, or a pasture reset after a wet summer, it is the standard tool.
Whatever the size, buy for the roughest ground you will actually mow, not the ground you wish you had. Clearing a fence line choked with brush calls for a very different cutter than trimming a clean pasture.
How do you match the cutter to your tractor?
Do not guess at power. Look up your tractor's PTO rating and its lift capacity in your manual, then compare it to the cutter manufacturer's listed requirements. The cutter should be at or below what your tractor can handle in lift, PTO and weight. A cutter too heavy for the lift will make the tractor unstable.
Check the PTO speed the cutter is built for. PTO speeds are commonly 540 and 1000 rpm, and a cutter must be matched to the speed your tractor puts out.
What features should you compare when shopping?
Spend your time on the parts that carry the load and protect you. A cheap deck with a weak gearbox is a poor bargain, while a well-built unit lasts across seasons of rough work.
Ask the dealer about each item below and for the manual's specifications, not just the brochure's.
- Gearbox and driveline: size, rating and whether the shaft has a slip clutch or shear protection
- Deck construction and skid shoes
- Blade type and how they attach
- Height adjustment method
- Shields, chains or rubber guards that reduce thrown objects
- Tail wheel or gauge wheel setup
- Warranty terms and local parts availability
What blade and deck choices fit the job?
Heavier brush calls for thicker blades and a stout deck. Light pasture needs less. If you mow near fences, ditches or outbuildings, a cutter with a side discharge shield or full rubber skirt reduces the risk of a thrown rock or wire.
Match the deck width to your gates and tractor. A very wide deck cuts more per pass but may not fit through a gate or turn on a small property. A smaller cutter you can run safely beats a big one you avoid using.
What safety rules go with a rotary cutter?
Rotary cutters throw objects at high speed and can pull a person into the driveline. Keep all shields, guards and chains in place, never run the PTO with someone near the cutter, and walk the field first to pick up wire, rocks and debris.
Shut off the engine and wait for the blades to stop before you leave the seat or clear a jam. Never disable a PTO safety device or shield. Wear hearing protection and keep bystanders and children far away. See NIOSH and extension guidance on PTO safety.
Before every mowing season, check the driveline shields turn freely, the slip clutch is serviced as the manual describes, and no blade is cracked or chipped.
How should you check a used cutter?
Look for cracked decks, bent blade spindles, worn blade carriers, leaking gearbox seals and missing shields. Spin the blades by hand with the tractor off and the PTO disconnected to feel for a rough bearing. Check the PTO shaft guard for damage.
A used cutter missing its shields is not a bargain, because the replacement parts and the safety risk may outweigh the savings. Bring the model number to the dealer to confirm that parts are available.
Sources and further reading
Organization homepages are linked so you can search them for current guidance on this topic.