16 Inch Lawn Mower Blade, for Ryobi 40V 16 Inch RY40104, P1102, P1100 Lawn Mower, Replaces 639180003

What It Is

This is a 16-inch replacement blade designed specifically for Ryobi 40V cordless lawn mowers with a 16-inch cutting deck. It is intended for residential use on small to medium lawns.

Fitment & Compatibility

Before buying, confirm your mower model matches one of these: Ryobi RY40104, P1102, or P1100. This blade replaces OEM part number 639180003. The blade measures exactly 16 inches from tip to tip, with a center hole diameter of 1 inch and a star-shaped drive pattern. It will only fit mowers with a 16-inch deck and the same drive pattern—do not use on 14-inch, 18-inch, or other deck sizes. Aftermarket, not OEM.

Key Things to Know

• Quality concerns: With a 3.7 rating from only 9 reviews, this blade may have inconsistent sharpness or balance out of the box. Check for wobble before mounting.
• Installation: Simple swap using a 15mm or 5/8-inch socket. Use a torque wrench to tighten to 35-50 ft-lbs. Always disconnect the battery before working.
• Common gotcha: The star drive pattern can wear over time; if your old blade’s center hole is stripped, the new blade may not seat tightly. Inspect the spindle for damage before installing.
• Maintenance: Sharpen or replace every 20-25 hours of use, or sooner if you hit rocks or roots.

Should You Buy It

If you own a Ryobi RY40104, P1102, or P1100 and need a budget-friendly replacement, this blade will work. But given the low review count and average rating, consider checking for a genuine Ryobi OEM blade if you prioritize long-term durability and consistent cut quality. This is fine for occasional use where cost matters most.