942-0640 742-0640 High Lift Mulching Mower Blade, Compatible with 20" Deck MTD Yard Machines Columbia Bo lens Walk Behinds Lawn Mower, Replace 742-0640, 942-0640, 742-0640, 490-100-M115, 1 Pack

What It Is

This is a high-lift mulching blade designed to fit 20-inch cutting decks on MTD, Yard Machines, Columbia, and Bolens walk-behind lawn mowers. It replaces OEM part numbers 742-0640, 942-0640, and 490-100-M115, and its curved, raised wings create stronger airflow for finer clippings and better bagging performance.

Fitment & Compatibility

Before buying, confirm your mower deck measures exactly 20 inches (center of blade shaft to deck edge). This blade fits most MTD-branded walk-behinds with that deck size, including Yard Machines, Columbia, and Bolens models from the 2000s onward. Check your current blade’s part number—if it ends in 742-0640, 942-0640, or 490-100-M115, this is a direct swap. Measure the blade’s length (20 inches end to end), center hole diameter (typically 1 inch), and thickness (about 0.25 inches). If your mower uses a different hole pattern or offset, this blade won’t fit. Always verify your owner’s manual or existing blade stamp before ordering.

Key Things to Know

• Quality: Aftermarket blade, but matches OEM specs. Steel is heat-treated for durability; edge holds up through a season of regular mowing.
• Installation: Easy if you have a wrench and block of wood to stop the blade from spinning. Torque the nut to 30–40 ft-lbs—hand-tight will cause wobble.
• Common gotchas: High-lift designs increase engine load—expect slightly more vibration and reduced runtime on electric mowers. Not ideal for wet grass (clogging risk) or very thick, tall growth (strain on small engines).
• Mulching vs. bagging: Works well for both, but if you only want to bag, a standard blade might be quieter.

Should You Buy It

Buy this if you have a 20-inch MTD/Yard Machines/Columbia/Bolens mower and want a reliable, affordable replacement that improves clipping fineness and bagging pickup. It’s a solid upgrade over a worn or standard blade, especially if you mow dry, thin-to-medium grass. Skip it for wet, heavy, or very tall grass—you’ll be better off with a low-lift or Gator-style blade.