MowerPartsGroup (3) Mulching Blades for Husqvarna 42" YTH Series & More 573953001, 539112078

What It Is

This is a set of three mulching blades designed for 42-inch cutting decks on Husqvarna YTH series tractors and select compatible models. They replace OEM part numbers 573953001 and 539112078, and are intended for mulching grass clippings into fine particles for nutrient recycling, not for bagging or side discharge.

Fitment & Compatibility

Before buying, confirm your deck measures exactly 42 inches (blade length is typically 20.5 inches per blade, but measure your existing blade from center hole to tip). These fit Husqvarna YTH22V46, YTH24V48, and many other YTH-series tractors with a 42-inch stamped deck. Also compatible with some Craftsman, Poulan Pro, and McCulloch models using the same OEM numbers. Check your deck’s blade mounting pattern—these use a standard oval center hole (0.75 x 0.5 inches) and a 1-inch diameter arbor hole. If your deck has a different spindle or blade retention system, they won’t work. Always cross-reference your model number with the manufacturer’s parts list.

Key Things to Buy

• Quality: Aftermarket blades made from hardened steel, but not OEM. They may be slightly lighter or thinner than originals, which can affect balance and wear life. Expect around 25-40 hours of mulching before needing replacement.
• Installation difficulty: Moderate. You’ll need a socket wrench, torque wrench (set to 35-45 ft-lbs), and a blade removal tool or block of wood to prevent spinning. Always disconnect the spark plug wire first.
• Common gotchas: Mulching blades require a clean, dry deck and sharp edges. Dull blades tear grass, leaving clumps. Never use them for bagging—they’ll clog the chute. If your deck has a mulch plug, keep it installed for best performance.
• Balance check: After installing, spin each blade by hand to ensure no wobble. Unbalanced blades vibrate the deck and can damage spindles.

Should You Buy It

Buy this set if you own a Husqvarna YTH-series tractor with a 42-inch deck, mulch your lawn regularly, and want a cost-effective replacement for OEM blades. It’s a good value for homeowners who don’t need premium OEM durability, but skip it if you require exact OEM specs or plan to bag or side-discharge frequently.