133-8181-03 112-8841-03 Toothed Mower Blade, Compatible with T oro Lawn Boy Walk Behind Mower 20 Inch Deck, Lawn Mower Blade Replace 112-8841

What It Is

This toothed mower blade (OEM cross-reference 133-8181-03 / 112-8841-03) is a replacement cutting blade designed specifically for Toro and Lawn Boy walk-behind mowers with a 20-inch deck. The toothed edge helps shred grass clippings finer for improved mulching performance.

Fitment & Compatibility

Before buying, verify these three things:

• Deck size: This blade fits only 20-inch cutting decks. Measure your deck width (blade tip to tip) to confirm.
• Model compatibility: Works with Toro 20010, 20011, 20012, 20015, 20017, 20020, 20021, 20022, 20024, 20025, 20027, 20030, 20031, 20032, 20333, 20334, 20335 and Lawn Boy 10683, 10684, 10685, 10686, 10687, 10688, 10689, 10690, 10691, 10692, 10693, 10694, 10695, 10696. Check your mower’s model number on the engine cowl or under the seat.
• Measurements: Blade length is 20 inches (tip-to-tip), center hole is 5/8-inch diameter, and blade thickness is 0.125 inches. Measure your old blade to confirm these match.

Key Things to Know

• Quality: Aftermarket blade, not OEM Toro. Users report it cuts well but may not hold an edge as long as genuine Toro blades. Expect 1-2 seasons of typical residential use.
• Installation: Straightforward swap—remove center bolt, replace blade, torque to 40-50 ft-lbs. Use a blade removal tool or block wood to prevent rotation. No special adapters needed.
• Gotcha: The toothed design is for mulching only. If you bag or side-discharge, a standard straight blade will perform better. Also, ensure the blade is oriented with the lift wings facing upward toward the deck.
• Balance: Aftermarket blades sometimes arrive slightly out of balance. Check with a blade balancer before installing to avoid vibration and bearing wear.

Should You Buy It

Buy this if you own a 20-inch Toro or Lawn Boy walk-behind and want a budget-friendly mulching blade for residential use. Skip it if you need OEM durability for heavy commercial cutting, or if you primarily bag or side-discharge—you’ll get better results with a standard straight blade.