--- title: "How to sharpen lawnmower and brushcutter blades | Zak Services" description: "Lawnmower and brushcutter blade sharpening at Zakservices Senica. A home guide, balancing and servicing. Obchodná 493/2A, phone and opening hours." url: "https://www.zakservices.sk/en/how-to-sharpen-mower-and-brushcutter-blades/" lang: "en" alternates: "sk": "https://www.zakservices.sk/ako-spravne-brusit-noz-kosacky-krovinorezy/" "en": "https://www.zakservices.sk/en/how-to-sharpen-mower-and-brushcutter-blades/" "de": "https://www.zakservices.sk/de/maehmesser-und-freischneidermesser-schaerfen/" "cs": "https://www.zakservices.sk/cs/jak-spravne-brousit-nuz-sekacky-a-krovinorezu/" "es": "https://www.zakservices.sk/es/como-afilar-cuchilla-cortacesped-y-desbrozadora/" "ru": "https://www.zakservices.sk/ru/kak-pravilno-tochit-nozh-kosilki-i-motokosy/" "uk": "https://www.zakservices.sk/uk/yak-pravylno-hostryty-nizh-kosarky-i-motokosy/" "fr": "https://www.zakservices.sk/fr/comment-affuter-lame-tondeuse-et-debroussailleuse/" "it": "https://www.zakservices.sk/it/come-affilare-lama-rasaerba-e-decespugliatore/" "hu": "https://www.zakservices.sk/hu/funyiro-es-fukasza-kes-elezese/" "pl": "https://www.zakservices.sk/pl/jak-ostrzyc-noz-kosiarki-i-podkaszarki/" "nl": "https://www.zakservices.sk/nl/maaimes-en-bosmaaierblad-slijpen/" "pt": "https://www.zakservices.sk/pt/como-afiar-lamina-corta-relva-e-rocadora/" "ro": "https://www.zakservices.sk/ro/cum-ascutiti-lama-masina-tuns-si-motocoasa/" "hr": "https://www.zakservices.sk/hr/kako-ispravno-ostriti-noz-kosilice-i-motorne-kose/" "sr": "https://www.zakservices.sk/sr/kako-ispravno-ostriti-noz-kosilice-i-trimera/" --- [Back to FAQ](https://www.zakservices.sk/en/faq/) # How to sharpen lawnmower and brushcutter blades correctly At Zakservices in Senica, we sharpen and balance lawnmower blades, check STIHL brushcutter blades and advise on DAKR. The home method is below. If you’re not sure, bring in the blade or the machine. ![Close-up of a lawnmower blade being sharpened by hand with a flat file in a vice (gloves)](https://www.zakservices.sk/assets/img/articles/mower-blade-filing.f54da9c0.jpg) **Blade sharpening** for lawnmowers and brushcutters is a service we routinely provide at **Zakservices** in Senica. A blunt blade tears the grass rather than cutting it, puts more load on the engine and leaves grass tips that turn brown. Sharpening and balancing the blade on a rotary mower (STIHL, STIGA, WOLF-Garten, Cub Cadet, SUPA TECHNIKA) or a STIHL brushcutter, and checking the blades on a DAKR drum mower, are all part of routine machine care. Below you’ll find a safety-focused guide in case you want to touch up the blade at home. If you’re not confident about removing it, the angle or the balancing, bring in the blade or the whole machine. We’ll assess whether it’s still worth sharpening or needs replacing, then sharpen and balance it, or have a replacement blade ready, depending on stock. ## What you’ll learn in this article - blade sharpening as a service in Senica - safety before sharpening - sharpening and balancing a rotary mower blade - brushcutters: metal blades or a mowing head - DAKR drum mower blades - when to sharpen and when to replace - FAQ and contact details ## Blade sharpening as a service in Senica At our shop at Obchodná 493/2A, we’ll sharpen and balance your rotary mower blade, check your STIHL brushcutter blade and advise you on DAKR drum mower blades. Just drop in during opening hours or give us a quick call first. **When it makes sense to come in straight away:** - the blade has hit a stone or a kerb and you’re not sure whether it can still be sharpened - the lawnmower vibrates after you’ve sharpened the blade at home - you don’t want to risk getting the deck removal or the tightening torque wrong - you need a replacement blade and aren’t sure of the type - it’s a Cub Cadet or SUPA TECHNIKA ride-on mower, where vibration costs more A touch-up at home makes sense when the blade is evenly blunt, straight and free of cracks. The aim of this article is to show you a safe method and also to help you recognise when it’s less stressful to leave the job to the workshop. ## Why a sharp blade is kinder to the machine and the lawn A blunt blade needs more revs and more force. The engine and the battery (on STIHL cordless models) work harder, the deck clogs more easily and the lawn looks ‘scraped’. A sharp cut seals the grass stem more cleanly, the lawn recovers faster and fuel or energy consumption goes down. The same goes for Cub Cadet and SUPA TECHNIKA ride-on mowers and for standard STIGA and WOLF-Garten lawnmowers: **the quality of the cut starts at the edge of the blade**, not in an advert about power. ## Safety before every job Sharpening without preparation is a common cause of injuries. Stick to this order: 1. **Switch off the engine** and let the blade come to a complete stop. 2. **Disconnect the spark plug** (petrol) or **remove the battery** (STIHL cordless). 3. With a STIHL brushcutter, put the machine down on a stable surface and make sure it can’t start accidentally. 4. Put on **safety glasses**, sturdy footwear and **cut-resistant gloves**. 5. Loosen the blade with the correct spanner. Lock it as the manufacturer’s manual says, not with your free hand against the edge. 6. After sharpening, check the mounting, the washers and the tightening torque against the manual for your model. Never sharpen the blade on a running machine. Never reach under the deck until the drive is disconnected. If you’d rather not remove the blade yourself, bring the machine to Zakservices. ## Sharpening a rotary mower blade A rotary mower has a horizontal steel blade under the housing (the deck). This is typical of STIHL, STIGA and WOLF-Garten, and of Cub Cadet or SUPA TECHNIKA cutting decks. ### Preparation and removal - Clean grass and mud off the deck (with a dry cloth or a plastic scraper). - Mark which way round the blade goes (which side faces up) so that you refit it the same way. - Once it’s off, check for **cracks, bends, chipped sections and a worn centre hole**. If you see a crack or a severe bend, **don’t sharpen it**. Replace the blade. We’ll help you choose a replacement, depending on stock. ### How to sharpen The aim isn’t a ‘razor for shaving’ but to restore the original edge angle and remove the same amount of metal at both ends. - Sharpen **only the upper bevel** of the cutting edge at its original angle, and leave the underside of the blade flat. The usual angle is around 30 degrees, but always respect the shape of the original. - Use a file, a sharpening stone or an angle grinder with a fine disc. With a grinder, work in **short passes** and cool the blade often so that the steel doesn’t overheat and turn blue. - Remove metal **equally on the left and right**. Asymmetry causes vibration. - Preserve the ‘air wings’ (the raised lifts) at the ends of the blade. Grinding them down impairs collection and mulching. - Don’t grind the blade down to a thin edge. A blade that is too sharp and thin catches on stones more easily and cracks. As a rough guide: in a typical home garden, a check and a light touch-up **1 to 3 times a season** is enough, depending on the area, the amount of sand and how often you mow. After hitting a stone, check the blade straight away. If you want to be sure of the angle and the balance, have the blade sharpened at Zakservices. ### Balancing the blade (an essential step) After sharpening, **always balance** a rotary mower blade. - Use a simple blade balancer, or hang the blade by its centre hole on a horizontal nail or screw. - The heavier side will drop. Carefully remove material from the heavier side (not from the edge, but from the heavier part) until the blade stays level. - Repeat until the balance is stable. An unbalanced blade causes: - vibration in your hands and in the bearings - faster wear of the crankshaft and the clutch - an uneven cut and noisier running On Cub Cadet and SUPA TECHNIKA ride-on mowers, the consequences of vibration are even more expensive (deck bearings, belts). You won’t regret balancing the blade. In our workshop, we balance blades as part of sharpening. ### Refitting - Clean the contact surfaces. - Make sure the direction of rotation and the side of the blade are correct. - Tighten the nut / bolt as the manual says. After the first few minutes of running (reconnect the spark plug or battery only after checking), switch off and disconnect the machine and check the tightness once more. ## Brushcutters: blades and cutting heads STIHL brushcutters do a different kind of work: edges, ditches, self-seeded saplings, denser growth. Sharpening depends on the type of cutting attachment. At Zakservices, we can check a metal blade and, depending on its condition, sharpen it or recommend a replacement. ### Metal blade / multi-purpose blade - Remove the blade only once the machine has stopped completely and the drive is disconnected. - Check for cracks around the mounting and the teeth. **Replace** a cracked blade rather than repairing it by welding in a home workshop. - Sharpen every tooth / every edge **equally**, keeping the original angle. - After sharpening, check that the blade sits straight and that the mounting parts (thrust plate, nut) are in the order given in the STIHL manual. - When working with a metal blade, always use the specified guard and personal protective equipment. ### Mowing head (trimmer head) You **don’t sharpen** trimmer line. Replace worn line with the correct diameter and profile for the head. If the line seems blunt, it often means: - the line is too short or too thin - it’s wound incorrectly - the head’s line exit eyelets are worn In that case, the answer is new line or new head parts, not a file. In the shop, we’ll advise you on the right line diameter for your STIHL head. ### When to choose a blade and when to choose line - **Line:** soft grass, lawn edges, finer work around fences. - **Metal blade:** denser growth, self-seeded saplings, places where line can’t cope (always as the manual says and with the right guard). If you’re mowing a whole meadow, it’s better to add a DAKR drum mower to your STIHL brushcutter. Sharpening a brushcutter blade won’t make up for having the wrong machine for the area. ## DAKR drum mower blades A DAKR drum mower cuts with a disc fitted with **movable (swinging) blades**. They often ‘swing out of the way’ when they hit stones, which protects the shaft, but the blades themselves wear. **In practice:** - Check the blades before the season and after every tougher mow with stones. - A light touch-up of the edge with a file can extend their life, as long as the blade isn’t deformed. - With heavy wear, chipping or uneven loss of material, **replace the set of blades**, not one blade ‘blindly’. A mismatched set makes the machine run less smoothly. - Use the correct mounting and locking parts as specified in the DAKR documentation. Sharpening drum mower blades makes sense when they are evenly blunt. If they’re damaged, replacing them is safer and often cheaper than risking vibration out on the meadow. We can assess the condition of the set at Zakservices. ## When to sharpen and when to replace | Condition of the blade | Recommendation | | --- | --- | | Just a blunt edge, blade straight, no cracks | Sharpen and balance (at home or in the workshop) | | Small nicks from sand | Touch up lightly, check the balance | | Bent blade | Replace (straightening is risky) | | A crack anywhere | Replace immediately | | Worn centre hole / ‘stretched’ mounting | Replace | | Little material left after repeated sharpening | Replace | | DAKR drum mower blades unevenly worn | Replace the set | **The rule:** if in doubt, replace the blade or bring it to us. A new blade costs less than a bearing, a shaft or an injury. ## Common sharpening mistakes - Sharpening only one side of a rotary mower blade - Overheating the steel with an angle grinder - Skipping the balancing - Grinding down the air wings - Fitting the blade upside down - Working without disconnecting the spark plug or battery - Keeping a cracked blade ‘for one more season’ In practice, each of these mistakes shows up as vibration, a poor cut or a repair that could have been avoided. If your lawnmower vibrates after you’ve tried at home, drop in to see us in Senica before you damage the bearings. ## How often to check the blade during the season - **Before the first mow:** a visual check, tightness and a touch-up if needed. - **After hitting** a kerb, a stone or a root: check it immediately. - **Mid-season:** with regular mowing, check the sharpness and balance after roughly 10 to 20 hours of work. - **In autumn:** clean, check and decide whether to sharpen or order a new blade before spring. On sandy ground, and if you often mow edges along paths, the blade blunts faster than on a clean lawn. ## Frequently asked questions (FAQ) ### 1. Do you sharpen lawnmower and brushcutter blades at Zakservices? Yes. We sharpen and balance rotary mower blades, check STIHL brushcutter blades and advise on DAKR blades. Just bring in the blade or the machine. ### 2. Can I sharpen the blade with an angle grinder? Yes, carefully and with a light touch. Work in short passes, cool the steel and keep the original angle. Always balance the blade afterwards. If you’re unsure, use a file or have the blade sharpened in the workshop. ### 3. Why is balancing essential on a lawnmower? An unbalanced blade vibrates. Vibration ruins bearings, shafts and comfort. The physics is the same for Cub Cadet, SUPA TECHNIKA, STIHL, STIGA and WOLF-Garten. ### 4. How can I tell that sharpening is no longer enough? A crack, a bend, a badly chipped edge, an oval centre hole or too little material left after repeated sharpening. In those cases, replace the blade. We’ll check the replacement type against our stock. ### 5. Is the trimmer line on a STIHL brushcutter sharpened too? No. Replace the line. Only metal blades are sharpened, and only if they have no cracks. ### 6. What about the blades on a DAKR drum mower? Check them regularly. If they’re evenly blunt, touch them up lightly. If they’re damaged or unevenly worn, replace the set. We can assess their condition in the shop. ### 7. How sharp should a lawnmower blade be? Sharp enough to cut paper or a grass stem cleanly, not sharp enough to shave with. A ‘razor’ that’s too thin is brittle and dangerous on impact. ### 8. Where in Senica can I get help with a blade and choosing a replacement? At Zakservices, Obchodná 493/2A. We’ll assess the condition of the blade, sharpen and balance it or prepare a replacement. You’ll find our phone numbers and opening hours below. ## Let us help you at Zakservices in Senica Bring in the blade or the whole machine. At Zakservices in Senica, we’ll **sharpen and balance** the blade, advise you on a replacement and, depending on current stock, help you choose the right blade for STIHL, STIGA, WOLF-Garten, Cub Cadet, SUPA TECHNIKA and DAKR lawnmowers and brushcutters. **Zakservices, s.r.o.** Obchodná 493/2A, 905 01 Senica (white building opposite the Kaufland car park) Phone: +421 904 446 915, +421 34 651 70 72 Email: zakservices@zakservices.sk Opening hours: Monday to Friday, 8:30 to 16:30 Website: [https://www.zakservices.sk](https://www.zakservices.sk) Please check the seasonal Saturday opening (April to June) by phone. We’ll confirm specific parts and stock with you in person. --- **Zak Services** Zak Services, s.r.o., authorised STIHL dealer · garden and outdoor machinery Authorised STIHL dealer Obchodná 493/2A, 905 01 Senica - [Home](https://www.zakservices.sk/en/) - [Services](https://www.zakservices.sk/en/services/) - [Brands](https://www.zakservices.sk/en/brands/) - [FAQ](https://www.zakservices.sk/en/faq/) - [Contact](https://www.zakservices.sk/en/contact/) - [Privacy notice](https://www.zakservices.sk/en/privacy/) - [+421 34 651 70 72](tel:+421346517072) - [zakservices@zakservices.sk](mailto:zakservices@zakservices.sk) © 2026 Zak Services, s.r.o.