8TEN LawnRAZOR Mower Blade for MTD Columbia Cub Cadet Walk Behind 20 inch Deck 942-0640 742-0640 (High-Lift)

What It Is

This is a high-lift replacement blade for walk-behind mowers with a 20-inch cutting deck, designed for MTD, Columbia, Cub Cadet, and other compatible brands. It’s optimized for bagging and side-discharge performance by creating stronger airflow to lift grass into the deck.

Fitment & Compatibility

Check these before buying:

• Deck size: Must be exactly 20 inches. Measure your current blade tip-to-tip if unsure.
• OEM reference numbers: Directly replaces MTD 942-0640 and 742-0640. Also fits many Cub Cadet, Troy-Bilt, Yard Machines, and Craftsman models using those OEM numbers.
• Center hole & measurements: Center hole is 5/8-inch round (not star-shaped). Overall length is 20 inches, blade width 2 inches, thickness 0.20 inches. Verify your spindle matches a 5/8-inch round hole.
• Brand compatibility: Not for all Cub Cadet walk-behinds—only those with a 20-inch deck that originally used a 942-0640 or 742-0640 blade. Check your owner’s manual or current blade part number.

Key Things to Know

• High-lift design: Produces strong suction for bagging but creates more drag on the engine. May strain smaller engines in thick, wet grass—keep engine speed at full throttle.
• Installation difficulty: Simple DIY job (wrench and socket). Torque blade bolt to 30-40 ft-lbs. Use thread locker if not already applied.
• Balance: Blades come unsharpened and may need balancing before use. A $10 blade balancer is worth it to avoid vibration and spindle wear.
• Not universal: Will not fit 21-inch decks, zero-turn mowers, or decks with a star-shaped spindle hole.

Should You Buy It

Buy this if you need a direct replacement for a worn 942-0640/742-0640 blade on a 20-inch walk-behind and prioritize bagging or side-discharge with strong lift. Skip it if your deck is not 20 inches, your spindle uses a star hole, or you mainly mulch—a mulching blade would serve better. At $22 with a 4.7-star rating, it’s a solid value for the specific fit.