Lawn Mower High Lift Mulching Blade for 20 inch Cutting Decks for MTD Columbia Yard Machines Cub Cadet Walk Behind 942-0640 742-0640

What It Is

This is a high-lift mulching blade designed to fit 20-inch cutting decks on walk-behind mowers from MTD, Columbia, Yard Machines, and Cub Cadet. It replaces OEM part numbers 942-0640 and 742-0640, and is built for fine clippings that get recut and dropped back into the turf.

Fitment & Compatibility

Before buying, confirm three things:

• Deck size: Must be exactly 20 inches (not 21 or 22).
• Blade measurements: Center hole is 7/8-inch round; blade length is 20 inches overall; width is roughly 2.5 inches; thickness is about 0.17 inches.
• Brand/model: Fits most MTD-built walk-behinds (e.g., Cub Cadet SC series, Yard Machines 11A series, Columbia 382 series). Check your mower’s model number or the blade part number stamped on the old blade. Aftermarket blade is a direct replacement for OEM 942-0640 and 742-0640.

Key Things to Know

• Lift vs. mulching: High-lift design pulls grass up for a cleaner cut but creates more suction, which can bog the engine in tall, wet grass. Not ideal for bagging.
• Installation: Easy with a socket wrench—just one center bolt. Torque to 35-45 ft-lbs. Always disconnect the spark plug first.
• Sharpness: Comes sharp but dulls faster than standard blades due to the aggressive lift. Plan to sharpen or replace every 10-15 hours of use.
• Balance: Aftermarket blades may need balancing before install. Use a blade balancer or nail in a wall to avoid vibration.

Should You Buy It

Buy this if you have a 20-inch MTD/Cub Cadet walk-behind and want better mulching performance than the stock blade. It’s a solid upgrade for clean, fine clippings on dry, maintained lawns. Skip it if you bag often or mow wet, thick grass—the high lift will clog and strain the engine.