Terre Products, Single Mulching Lawn Mower Blade, 16 Inch Deck, Compatible with Ryobi RY40100, RY40104, P1102, P1100, Replacement for 639180003, 639180001

What It Is

This is a single mulching blade designed for 16-inch electric Ryobi mowers, cutting grass into fine clippings that decompose back into the lawn. It’s a direct replacement for worn or damaged OEM blades on select battery-powered models.

Fitment & Compatibility

• Deck size: Only for 16-inch cutting decks. Measure your deck width—don’t guess.
• Models: Confirmed fit for Ryobi RY40100, RY40104, P1102, and P1100. Not guaranteed for other 16-inch Ryobi models (e.g., RY40180).
• OEM numbers: Replaces 639180003 and 639180001. Verify your current blade’s part number (stamped on blade or in manual).
• Measurements: Blade length is 16 inches; center hole diameter and offset must match your spindle. Check your old blade’s hole size and thickness—aftermarket blades can vary slightly.
• Aftermarket note: This is not an OEM Ryobi blade. While compatible, tolerances may not be identical to factory parts.

Key Things to Know

• Installation difficulty: Easy—requires a wrench and possibly a blade removal tool. Torque the bolt to 30-40 ft-lbs; overtightening can strip the spindle.
• Mulching vs. bagging: This blade is designed for mulching only. It won’t lift grass into a bagger effectively. If you need to switch between modes, consider a universal blade.
• Quality concerns: Mixed reviews (3.9 stars). Some users report blades arriving slightly bent or unbalanced. Inspect visually and balance on a screwdriver before installing.
• Sharpness: Usually comes sharp, but touch up with a file after a few uses—dull blades tear grass, inviting disease.

Should You Buy It

If you own one of the listed Ryobi models and need a quick, budget-friendly mulching replacement, this blade works. But for better balance and longer life, consider the OEM Ryobi 639180003 (around $25). Skip it if you need a bagging blade or have a different 16-inch Ryobi model—check fitment first.