A well-maintained lawn starts with a sharp mower blade. Dull blades tear at your grass, leaving behind a ragged, uneven finish that can stress your lawn and encourage disease. At STIHL Shop Mount Maunganui, we stock the full range of Masport lawn mowers and provide professional servicing for all makes and models—so we know just how important it is to keep your blades in top condition.
If you're aiming for a pristine cut every time you mow, follow our step-by-step guide to sharpening your mower blades safely and effectively.
If your mower starts leaving behind torn or uneven grass, it’s likely time to sharpen the blade. But don’t wait for the signs—regular inspections help prevent performance issues.
• Routine maintenance: Sharpen your blade after every 20–25 hours of mowing.
• Visual inspection: Check the blade regularly for wear and tear.
• Cracks or major damage? Don’t sharpen—replace the blade immediately.
Your local STIHL SHOP has the tools and expertise to sharpen your mower blade quickly and precisely. But if you’re confident and have the right gear, here’s how to do it yourself.
What You’ll Need:
• Vice
• Work gloves
• Spanner
• Monkey or pipe wrench
• File
• Grinding stone or whetstone
• Blade balancer
Always disconnect your mower before starting work:
• Electric: Unplug from mains and coil the cord safely.
• Cordless: Remove the battery completely.
• Petrol: Disconnect the spark plug to prevent accidental starting.
To access the blade:
• Electric mowers: Can usually be tilted or turned upside down.
• Petrol mowers: Tilt to a maximum of 45°, with the carburettor facing upwards. This prevents oil from leaking into the air filter.
• Wear gloves to protect your hands.
• Use a spanner or wrench to turn the bolt anti-clockwise (right-hand thread).
• If the bolt is tight, wedge a wooden block to stop the blade from rotating or ask someone to assist.
• Before sharpening, scrub off all grass build-up.
• Inspect closely—if you find any cracks, replace the blade rather than sharpening.
Use a vice to hold the blade in place.
Tip: Place a piece of leather or cloth between the vice jaws and the blade to prevent scratches.
• Use a metal file or grinding stone.
• File in one direction, following the blade’s existing edge.
• Maintain a 30° angle for optimal cutting performance.
• Continue until the edge is clean, smooth, and uniform.
STIHL Tip: Rubbing a bit of chalk on your file helps produce a smoother finish.
• Place the blade on a balancer to check for even weight.
• If one side dips, file a bit more from that side.
• Repeat until the blade stays perfectly level—this prevents vibration and uneven mowing.
Once balanced, reinstall the blade using the same bolt and tighten securely. Reconnect the power source and give your mower a test—your lawn should now be getting the clean cut it deserves.
Prefer to leave it to the experts? Drop your mower into STIHL Shop Mount Maunganui, Tauranga’s trusted service centre for Masport and all leading mower brands. We'll ensure your blades are sharpened or replaced to professional standards—keeping your mower performing at its best.
Visit us today for expert advice, parts, and servicing that keeps your garden looking sharp.
