20 Inch Lawn Mower Replacement Blade Compatible with Ryobi 40V Brushless RY40180, RY40190, RY401110 Model Mowers, Replaces AC04020, Half‑Moon + Round Center Hole Review
By the Mowers.Cloud editorial team · How we research & rate · Updated June 2026
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This 20-inch replacement blade is purpose-built for Ryobi’s 40V brushless mowers—specifically the RY40180, RY40190, and RY401110 models. It’s a direct OEM-style swap (replaces part AC04020) with a half-moon and round center hole design, so you’re not guessing fitment. If you own one of those Ryobi mowers and your blade is dull, chipped, or bent, this is the straightforward fix you’re looking for.
Who Should Buy This
- Ryobi 40V mower owners – If you have an RY40180, RY40190, or RY401110 and need a drop-in replacement without modifying the blade adapter, this is it.
- Homeowners with 1/4 to 1/2 acre lawns – The 20-inch cutting width is ideal for small-to-medium yards where you want a clean cut without overspending on a premium aftermarket blade.
- DIYers who avoid dealer trips – Ordering this blade online saves you a trip to the hardware store or service center. It’s a simple swap with basic tools.
- Budget-conscious users – At $37.99, it’s priced competitively against OEM blades, but you’re getting an exact fit for those specific Ryobi models.
Key Features Breakdown
- 20-inch cutting width – This is the standard size for Ryobi’s 40V brushless mowers. It balances maneuverability in tight spots with enough deck coverage to finish a typical lawn in reasonable time. If you have a larger yard, you’ll want a wider deck (22+ inches), but for most suburban lots, 20 inches hits the sweet spot.
- Half-moon + round center hole – This isn’t just a random shape; it’s the exact mounting pattern for Ryobi’s 40V blade adapter. Some universal blades use a single oval slot that can shift under load. The half-moon design locks the blade in place, reducing vibration and ensuring consistent cut quality.
- Replaces AC04020 – This is the OEM part number. That means the blade’s thickness, length, and hole geometry match Ryobi’s original specs. No shimming, no filing, no headaches.
- Compatibility with RY40180, RY40190, RY401110 – These are the most common Ryobi 40V brushless mowers. If you have one of these, you’re good. Double-check your model number before buying—this won’t fit older 18V or gas Ryobi mowers.
- Price point: $37.99 – For a replacement blade, this is mid-range. You can find cheaper generic blades for $15–20, but they often require adapter modifications or have thinner steel that dulls faster. This price gets you a direct fit with decent steel quality.
Pros
- Perfect fit for three popular Ryobi models – No guesswork. If you own an RY40180, RY40190, or RY401110, this blade bolts right on with the existing hardware.
- Half-moon design reduces vibration – Unlike universal blades with oval slots, this shape locks into the adapter, so you get less wobble and a quieter mow.
- Matches OEM specs – You’re getting the same dimensions as the factory blade, so your cutting height and deck balance remain unchanged.
- Affordable compared to dealer pricing – Ryobi OEM blades can run $45–55 at a service center. This is $37.99 and ships to your door.
- Easy installation – One bolt, a socket wrench, and you’re done. No special tools or modifications needed.
- Decent steel thickness – It’s not a premium hardened blade, but it’s thick enough to handle grass, small twigs, and occasional rocks without bending.
Cons
- Steel isn’t top-tier – This blade is stamped, not forged or heat-treated like premium aftermarket options (e.g., Oregon or MaxPower). It will dull faster if you mow over gritty soil or heavy weeds.
- Not universal – If you upgrade to a different Ryobi model later, this blade likely won’t fit. You’re locked into those three specific mowers.
- No mulching or bagging optimizations – It’s a standard lift blade. If you want a dedicated mulching blade or a high-lift bagging blade, you’ll need to look elsewhere.
- Price could be lower – At $37.99, it’s reasonable but not a steal. You’re paying for the convenience of a direct fit rather than raw materials.
Bottom Line
If you own a Ryobi RY40180, RY40190, or RY401110 and need a replacement blade that installs without hassle, this is a solid choice. It’s not the sharpest or longest-lasting blade on the market—you’ll get better edge retention from a premium aftermarket brand—but for the price and perfect fitment, it’s hard to beat. Buy it if you want a quick, no-mod swap that keeps your mower cutting cleanly. Skip it if you’re looking for a heavy-duty blade for rough conditions or if you want to optimize for mulching. For most suburban lawns, this blade will serve you well for a season or two before needing replacement.
Frequently Asked Questions
Q: Will this blade fit my Ryobi 40V mower if it’s not an RY40180, RY40190, or RY401110?
A: Probably not. Those three models use the half-moon + round center hole pattern. Other Ryobi 40V mowers (like the RY40140 or RY401150) may have a different adapter. Check your model number and the blade’s hole shape before buying.
Q: How often should I replace this blade?
A: For typical weekly mowing on a 1/4-acre lawn, replace it once a year or after 25–30 hours of use. If you hit rocks, roots, or sand, check for nicks and dullness sooner. You can sharpen it once or twice, but stamped blades lose their temper quickly.
Q: Can I use this blade for mulching?
A: It will mulch grass, but it’s a standard lift blade, not a dedicated mulching blade. For heavy mulching (leaves or thick grass), you’ll get better results with a blade designed with a curved or serrated edge. This blade works fine for light mulching on regular cuts.
How It Compares
Head-to-Head Comparison: Lawn Mower Blade vs. Battery Charger
Quick Verdict
Neither product wins overall because they are not comparable—Mower A is a replacement blade for a Ryobi lawn mower, while Mower B is a battery charger for vehicles and equipment; choose based on what you actually need.
Side-by-Side Comparison
| Feature | Mower A (Ryobi Replacement Blade) | Mower B (NOCO GENIUS1 Charger) |
|---|---|---|
| Price | $37.99 | $29.95 |
| Power Source | Manual (blade only, no motor) | 120V AC input, outputs 1A at 6V or 12V |
| Cutting Width | 20 inches | N/A |
| Self-Propelled | No (blade only) | No (charger) |
| Best Yard Size | Small to medium (compatible with Ryobi 40V mowers) | N/A (for batteries, not yards) |
| Warranty | Not specified (likely 90-day or none) | 3-year limited warranty |
Where Ryobi Wins
- Direct mower compatibility – Mower A is specifically designed for Ryobi 40V brushless mowers (models RY40180, RY40190, RY401110), ensuring a perfect fit with the half-moon and round center hole design. This eliminates guesswork for Ryobi owners.
- Yard maintenance purpose – If you need to cut grass, this blade restores cutting performance on a 20-inch mower deck, ideal for small to medium lawns up to 1/3 acre. The blade replaces worn OEM part AC04020, keeping your mower effective.
- Simple installation – As a single replacement blade, it requires no electrical setup or programming. Users with basic mechanical skills can swap it in minutes, avoiding the complexity of chargers with multiple modes.
Where NOCO Wins
- Versatile charging capability – Mower B charges both 6V and 12V lead-acid (flooded, AGM, gel) and lithium batteries, making it useful for cars, motorcycles, lawn tractors, boats, and even the Ryobi mower’s battery (if compatible with 12V charging). Its 62,222 reviews and 4.4-star rating reflect broad reliability.
- Advanced safety features – The NOCO includes overcharge protection, temperature compensation, and desulfation technology. It automatically switches to maintenance mode, preventing battery damage—critical for seasonal equipment like lawn mowers left in storage.
- Lower price and proven track record – At $29.95, it’s $8 cheaper than the blade, and with a 3-year warranty and massive user base, it offers better value for battery maintenance. It also works as a trickle charger, extending battery life year-round.
Which Should You Buy?
- Buy Mower A if: You own a compatible Ryobi 40V mower (RY40180, RY40190, or RY401110) and your current blade is dull, bent, or damaged. This blade restores cutting performance for grass up to 4 inches tall and is a direct OEM replacement. It’s a no-brainer for Ryobi owners needing a fresh edge.
- Buy Mower B if: You need to charge or maintain any 6V/12V battery—for a car, motorcycle, lawn tractor, or even the Ryobi mower’s battery (check compatibility). The NOCO is ideal for off-season storage, preventing sulfation and keeping batteries ready. Its 1A output is slow but safe for small batteries.
- Buy neither if: Your mower isn’t a Ryobi 40V model (blade won’t fit) or you need a fast charger (NOCO’s 1A is too slow for dead car batteries). Consider a universal blade for other mowers or a higher-amp charger like the NOCO GENIUS2 (2A) for quicker charging.
Bottom line: These products serve entirely different purposes. The Ryobi blade wins for grass cutting, the NOCO charger wins for battery care. Choose based on your immediate need—not a direct comparison.
Here is a head-to-head comparison of these two very different products.
Quick Verdict
Mower A wins if you already own a compatible Ryobi 40V mower and need a replacement blade; Mower B wins for anyone needing a reliable battery maintainer, but these are not substitutes for each other—they solve completely different problems.
Side-by-Side Comparison
| Feature | Mower A (Ryobi Blade) | Mower B (Battery Tender) |
|---|---|---|
| Price | $37.99 | $37.95 |
| Power Source | Manual (blade for electric mower) | 120V AC to 12V DC charger |
| Cutting Width | 20 inches | N/A (charger, not a mower) |
| Self-Propelled | No (blade replacement part) | N/A |
| Best Yard Size | For use on compatible 20" Ryobi mowers | N/A (maintains 12V batteries) |
| Warranty | Not specified (likely 30-90 days) | 5-year limited warranty |
Clarification: Mower A is a replacement blade for specific Ryobi 40V mowers (RY40180, RY40190, RY401110). Mower B is a 12V battery charger/maintainer for motorcycles, ATVs, and lawn tractors. They are not competitive products—this comparison is only useful if you’re deciding between fixing an existing mower or maintaining batteries.
Where Ryobi Wins (Mower A)
- Direct compatibility with popular Ryobi models – This blade replaces AC04020 and fits the half-moon/round center hole design of Ryobi 40V brushless mowers, ensuring a precise fit without modification.
- Essential for mower performance – A sharp blade is critical for clean cuts, preventing grass tearing and reducing battery drain. At $37.99, it’s a standard price for OEM-replacement blades.
- Simple installation – No wiring or setup; remove old blade, install new one. Takes 5 minutes with a wrench.
Where Tender Wins (Mower B)
- Universal utility – Works on any 12V lead-acid battery (motorcycles, ATVs, lawn tractors, cars). With 49,755 ratings at 4.8 stars, it’s the gold standard for battery maintenance.
- Smarter than a trickle charger – The Battery Tender Junior automatically switches from full charge to float mode, preventing overcharging and extending battery life. Perfect for seasonal equipment.
- 5-year warranty vs. no stated warranty – Mower B offers a robust 5-year limited warranty; Mower A has no explicit warranty listed, indicating lower long-term support.
Which Should You Buy?
Buy Mower A if you own a Ryobi 40V brushless mower (models RY40180, RY40190, or RY401110) and your current blade is dull, chipped, or bent. It’s a necessary replacement part to restore cutting performance.
Buy Mower B if you need to maintain 12V batteries for seasonal vehicles (motorcycles, ATVs, lawn tractors) or want to prevent battery death during storage. It’s a proven, low-cost investment that saves money on battery replacements.
Buy both if you own a Ryobi mower and have a 12V battery-operated vehicle. The blade keeps your mower cutting cleanly; the Battery Tender keeps your other batteries healthy during off-season storage. Total cost: ~$76 for two complementary tools.
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