How to Properly Remove Nicks When Sharpening Mower Blades with an Angle Grinder

Maintaining sharp mower blades is essential for achieving a clean, healthy cut on your lawn. If you're using an angle grinder to sharpen your blades, you may wonder what to do about those inevitable nicks along the cutting edge. Should you grind them out completely or just sharpen around them? Here's a practical guide based on real-world experience.

Do Nicks Really Matter?

It might be surprising, but minor nicks usually don't affect mowing performance much. Mower blades spin at around 3,000 RPM, meaning that even if a nicked portion of the blade misses a grass blade, another sharp section quickly follows to complete the cut. As long as the blade remains balanced and sharp, small imperfections are nothing to worry about.

Correct Sharpening Angle Matters More

Most mower blades are designed to have a cutting edge angle of 30 to 35 degrees, not 45 degrees. Keeping the correct factory angle ensures optimal lift and airflow, which is crucial for pulling the grass upright before cutting. Sharpening at too steep an angle, like 45 degrees, may result in a longer-lasting edge but will compromise cutting performance by reducing lift.

When sharpening, focus on restoring the original edge by grinding just enough to remove the rounded, dulled section. You don’t need to eliminate every small nick—doing so can unnecessarily remove a lot of material, risking blade imbalance.

When to Grind Out a Nick

If you encounter a large nick, you have two options:

• Lightly grind the area as you sharpen naturally; the nick will disappear over time after a few sharpening sessions.
• If the nick is severe and threatens blade balance or safety, replace the blade entirely.

Remember, the tip of the blade is where most of the cutting happens. Minor nicks further up the blade are less critical.

Final Thoughts

Sharpening mower blades isn't about achieving a perfect-looking edge—it's about maintaining the correct angle, balance, and sharpness. Small nicks are normal and can often be ignored unless they become a safety issue.

If you're looking for a reliable angle grinder to make the sharpening process easier and more efficient, we highly recommend the RedhawkPro angle grinder. It features a high-performance brushless motor, a high-strength spindle, and a powerful battery that ensures long-lasting performance even under heavy use. A great choice for both professionals and DIYers who demand quality and durability.