UDC Parts 103-6401 Mower Blades Replacement for Exmark 48 Inch Quest SP X Series 103-6401-S QST22BE482 103-6381-S 103-6381 103-6391-S 103-6391 103-6396 RAE708GEM48300 / High Lift Mulching 3 Pack

What It Is

This is a 3-pack of high-lift mulching blades designed for 48-inch Exmark Quest SP X Series zero-turn mowers. They replace OEM part numbers 103-6401-S, 103-6381-S, 103-6391-S, and several others, intended for cutting grass and bagging with improved airflow.

Fitment & Compatibility

• Deck size: 48 inches (3 blades per deck).
• Exact models: Exmark Quest SP X Series models QST22BE482, RAE708GEM48300, and others using OEM blades 103-6401-S, 103-6381, 103-6381-S, 103-6391, 103-6391-S, 103-6396. Also fits select Exmark Lazer Z and Radius X models with a 48-inch deck (verify your OEM part number).
• Measurements: Blade length ~18.25 inches, center hole ~1 inch, oval drive hole pattern. Confirm blade thickness (likely 0.1875 inch) and that your spindle bolt pattern matches.
• Before buying: Check your current blade’s part number (stamped on blade). Measure center hole diameter and bolt pattern. These are aftermarket—quality is high, but not OEM. Ensure your deck accepts high-lift blades (some lower-horsepower models may struggle with lift).

Key Things to Know

• Installation: Easy—remove old blades with a socket wrench, install new ones with the lift wings facing up. Torque bolts to 70-80 ft-lbs. No special tools needed.
• Performance: High-lift design improves bagging and side-discharge but increases load on the engine. May not suit wet or thick grass (can clog).
• Durability: Heat-treated steel, good edge retention. Balanced out of the box (check with a balancer if you’re picky). Sharpens well.
• Gotcha: Ensure blade orientation matches your deck’s spindle rotation (all three same direction). Some users report slightly thinner metal than OEM—still holds up for residential use.

Should You Buy It

If you own a 48-inch Exmark Quest SP X and want reliable, affordable blades for mulching or bagging, this 3-pack is a solid value. It’s not OEM, but it’s well-reviewed and works for most homeowners. Avoid if you need heavy-duty commercial blades or have a deck that struggles with high-lift designs.