AC04020 Blade for Ryobi 20 Inch 40V Brushless Mowers, Lawn Mower Blade Replacement Compatible with Ryobi RY40180, RY40190, RY401110, RY401120 Mowers

What It Is

The AC04020 is a replacement blade designed specifically for Ryobi 20-inch 40V brushless mowers. It cuts grass by spinning at high speed to create lift and a clean shear, intended for residential use on standard lawns.

Fitment & Compatibility

Before buying, confirm your mower has a 20-inch cutting deck and is one of these models: RY40180, RY40190, RY401110, or RY401120. The blade measures 20 inches overall length with a 5-point star center hole (not a standard oval or round hole). Measure your existing blade’s length and hole shape—if it’s different, this won’t fit. This is an aftermarket replacement, not OEM Ryobi. Check your blade bolt size (typically 5/16″ or 3/8″) and ensure the included hardware matches.

Key Things to Know

• Quality concerns: With a 3.5/5 rating, some users report blade dulling faster than OEM or being slightly out of balance. Inspect for warping before installation.
• Installation difficulty: Easy—requires a wrench or socket to remove the center bolt. Use a blade removal tool or block the blade with wood to prevent spinning. Torque the bolt to 30-40 ft-lbs.
• Common gotcha: The blade may sit slightly higher or lower than OEM, affecting cut height settings. Test on a small area first.
• Star hole alignment: Ensure the star pattern matches your mower’s spindle exactly; a loose fit will cause vibration and poor cutting.

Should You Buy It

Buy this if you need a quick, budget-friendly replacement for a Ryobi 20-inch 40V mower and don’t mind slightly shorter blade life or a possible balance issue. Skip it if you want OEM durability or have a different deck size—spend a few dollars more for the genuine Ryobi blade for consistent performance.