16 Inch Lawn Mower Blade for Ryobi RY40100, RY40104, P1102, P1100, Replace 639180003, 639180001, Heavy Duty Steel, Sharp & Durable, Fits 16" Deck

What It Is

This is a 16-inch replacement blade for Ryobi 40V brushless mowers, designed to cut grass on residential lawns. It replaces OEM part numbers 639180003 and 639180001, and fits models RY40100, RY40104, P1102, and P1100.

Fitment & Compatibility

Check your deck size first. Measure your mower deck from blade tip to blade tip—must be exactly 16 inches. This blade will not fit 20-inch or 21-inch decks.

Model-specific fit: Confirmed for Ryobi RY40100, RY40104, P1102, and P1100. If your model isn’t listed, verify the OEM part number (639180003 or 639180001) on your old blade or in the manual.

Aftermarket vs OEM: This is a third-party blade, not Ryobi-branded. Check that the center hole diameter matches (typically 1-inch, but measure yours). Also confirm the blade thickness—should be similar to OEM (around 0.15 inches) to avoid wobble.

Other considerations: Ensure the blade’s offset and air lift design matches your mower’s discharge chute orientation. Wrong offset can cause poor grass ejection or excessive vibration.

Key Things to Know

• Installation difficulty: Easy—requires a socket wrench and blade stop tool. Always disconnect the battery before flipping the mower.
• Quality: Heavy-duty steel is thicker than some budget blades, but the 3.6-star rating suggests possible balance issues. Check balance before installing; if it wobbles, return it.
• Sharpness: Pre-sharpened but dulls faster than OEM on rocky or sandy soil. Plan to sharpen every 10-15 hours of use.
• Common gotcha: The center hole may be slightly undersized on some units. File it gently if it doesn’t slide onto the spindle freely—forcing it can strip the bolt.

Should You Buy It

Buy this if you need a budget-friendly replacement for a Ryobi 16-inch mower and are comfortable checking blade balance and fitment. Skip it if you want guaranteed OEM fit, longer edge life, or a higher-rated blade—invest in a Ryobi genuine part instead.