CUB CADET 490-110-M178 50" Xtreme Mulch Blade Set Zero-Turn ZT2 Ultima SX S50 RZT LX KW

What It Is

This is a set of three 50-inch Xtreme mulching blades designed for Cub Cadet zero-turn mowers, specifically engineered to finely chop grass clippings for nutrient recycling. It’s intended for use on large residential or commercial properties where leaving no visible clippings is a priority.

Fitment & Compatibility

Before buying, confirm your mower has a 50-inch stamped deck and is one of these Cub Cadet models: ZT2 Ultima SX, S50, RZT LX, or KW series. This is an OEM Cub Cadet part (OEM #490-110-M178), so it’s a direct replacement for the factory blades. Measure your existing blades: they should be approximately 16.5 inches long, 2.5 inches wide, with a 1-inch diameter center hole and 0.5-inch offset. Do not assume it fits non-Cub Cadet decks—aftermarket decks often use different hole patterns or thicknesses.

Key Things to Know

• Quality: OEM-grade hardened steel with a painted finish. Holds an edge well for normal residential use but may dull faster on sandy or rocky soil.
• Installation difficulty: Moderate. Requires a socket wrench and torque wrench (recommended torque: 70-90 ft-lbs). Always lift the deck and disconnect the spark plug before working.
• Common gotchas: The mulching design creates more lift than standard blades—if your deck is heavily caked with grass, clean it first to avoid unbalanced spinning. Also, these blades are not for bagging; they’ll clog chutes if used with a bagger.
• Performance note: Best results with dry grass. Wet or tall grass will clump; mow more frequently or at a higher deck setting.

Should You Buy It

If you own a compatible Cub Cadet zero-turn with a 50-inch deck and want top-quality mulching without clippings, this set is a reliable OEM choice. It’s overkill for bagging or standard discharge use, but for dedicated mulching on large lawns, it’s worth the price. Skip it if you need blades for a different brand or deck size.