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How to Sharpen Hedge Trimmer Blades

Hedge trimmer blades require regular sharpening to keep them working effectively. Sharp blades on a hedge trimmer make clean cuts on tough woody branches, easily slice through dense hedge foliage, and keep hedges and shrubs looking neat and tidy.

when to sharpen trimmer blades

However, thick woody stems, plant resin, and cutting tough leaves dull blades, resulting in reduced performance. A blunt blade means you will have to exert more effort to keep your hedges and shrubs trimmed. But there’s another issue if you don’t sharpen hedge trimmer blades—the working life of the trimmer will be significantly reduced.

Have you noticed that trimming shrubs and hedges requires more effort? Do hedge plants have a disheveled appearance after using an electric hedge trimmer? Do you want to increase the performance of your cordless hedge trimmer and increase runtime? If so, this article is for you. Please read on to find the answer to these questions and more.

When Should you Sharpen Trimmer Blades?

All types of cutting instruments require regular sharpening. But how can you know when to sharpen the blunt blade on your hedge cutter? Of course, much depends on how often you use it. However, there are tell-tale signs that trimmer cutting blades require sharpening.

Signs that your blades on the hedge trimmer need sharpening include the following:

  • The ends of cut branches have a rough or frayed edges
  • There is more resistance when cutting hedge foliage
  • Branches keep getting jammed in the blades
  • The trimmer heats up more than usual
  • A battery-operated trimmer has reduced runtime, despite being fully charged.

It is easy to sharpen a hedge trimmer yourself at home. All you need is a flat file for sharpening, a whetstone, resin solvent, water, and a soft cloth. Of course, when handling sharp metal blades, protective gloves and safety glasses are always highly recommended.

Of course, the easiest way to sharpen hedge trimmer blades is to take the trimmer to a specialist. However, sharpening trimmer blades is so straightforward that it easier and cheaper to do it yourself.

Different ways to sharpen your blades

The two primary ways to sharpen blades on a hedge trimmer are to use a file or a power grinder. Both sharpening methods have pros and cons. Using a file is the simplest way and cheapest. It also gives you a high level of control. However, it requires time and patience.

A power grinder will enable you to sharpen the teeth on the blade in super-fast time. However, an angle grinder is dangerous because of the speed of the stone disc and sparks flying everywhere. In addition, there is an increased risk of the blades slipping or grinding off more than is necessary.

In general, using a fine-toothed file to sharpen hedge cutter blades is the easiest and safest way for most homeowners. However, if you have skill using a power grinder, this will make the sharpening process faster.

What is the best way to sharpen hedge trimmers?

Three factors determine the best way to sharpen hedge trimmer blades — precision, safety, and speed.

If you are looking for precision, the best way to sharpen cutting teeth on a hedge trimmer is with a file. Although it is more work than a grinder, you can sharpen the blades to the desired degree and ensure that all cutting edges are equally sharpened.

Suppose you want to sharpen trimmer blades quickly and with less effort. If you know how to use a grinder, that is the fastest way. But it’s vital to remember that sharpening blades with a grinder takes a lot of skill. So, if you’ve never sharpened garden tools before, it’s best to use a flat file.

Safety is paramount when working with sharp garden tools. Therefore, a handheld mill file is the recommended sharpening method for most people. As a result, you will do a better job and minimize the risk of serious injury.

Tip: If using a grinder, then safety gear is essential. This includes protective eye goggles and a pair of heavy gloves.

How to Sharpen Hedge Trimmers with a File

when to sharpen trimmer blades

Sharpening hedge trimmers is a simple procedure that anybody can do. First, remove the debris from the blades. Next, align the blades for sharpening. Then use the flat file to restore the sharpness to the trimmer’s teeth. But remember always to use safety gloves when working with sharp objects.

Here are the five steps to ensure your electric or cordless trimmer cuts like new and is always in peak condition:

Step 1. Clean the blades

Before taking the file to each blade, the first step is to remove debris and old tree sap. So, using a wire brush and cleaning solution, brush the blades to get rid of stubborn grime. Then use resin removing solution and a clean cloth to remove the rest of the dried sap.

Step 2. Align the blades

Before filing the blades, it’s crucial to align them. First, put on a pair of gloves and press the teeth together on a dual-action blade. Or you could use the handle of an old screwdriver to safely shift the blades into place.

Step 3. Use a flat file to sharpen blades

Using a forward motion, run the mill file down the edge of each blade, keeping it at the same angle as the cutting edge. Remember only to file in one direction for a perfectly sharp blade—not backward and forward. Continue filing until the tooth edge becomes shiny and sharp.

Top tip when sharpening hedge trimmer blades: Count the number of file strokes for each blade. Then use the same number for sharpening each one to get consistent results.

Step 4. Deburr blades with a whetstone

deburr blades with a whetstone

After sharpening the blades, you should remove the burrs from the undersides of the blades. Therefore, turn the trimmer upside down and carefully use a whetstone to smooth the sharpened steel.

Step 5. Apply blade protection

Before storing the hedge trimmer, you should use a resin solvent, 3-in-1 oil, or special oil on the blades. Apply the oil to a soft, clean cloth and carefully wipe down the entire edge of each blade. This protects the blades from rust and increases performance.

How do you sharpen a hedge trimmer with a grinder?

If you are experienced with a power grinder, you can use this tool to sharpen hedge or shrub trimmer blades. Although faster than filing, it’s not recommended for beginners. This is because it’s easy to remove too much steel from the blade, shortening its lifespan.

Here are the three steps to ensure your corded, battery-powered, or gas trimmer cuts like new:

Step 1. Prepare the trimmer blades for sharpening

Use a steel wire brush and resin-removing solution to remove hardened resin and grime from the blade before sharpening. Then use a cloth and resin remover to clean the blades. After that, use the handle of an old screwdriver to align the steel blades.

Clamp the grinder to a workbench and put on protective goggles and heavy work gloves for safety.

Step 2. Use a grinder to sharpen hedge trimmer blades

Using a grinder, carefully grind the cutting edges at the same angle as the blades, applying minimal pressure. Usually, running the grinder two or three times over the blade is enough. Once you are satisfied with the sharpness, repeat the process on each blade.

After grinding all the blades, don’t forget to run a whetstone along the underside of each blade. This is to remove burrs that occur on the blades during filing.

Step 3. Lubricate the blades

After using the grinder to sharpen the hedge cutter blades, apply a little lubrication oil with a clean cloth.

Frequently asked question about Sharpening Blades on a hedge trimmer

How often do you sharpen hedge trimmers?

It’s recommended to sharpen trimmer blades after every 50 hours of use. Or you can wait until you see visible signs of wear. Routine maintenance is crucial to maximizing the lifespan of your hedge clipper. This will mean that you get many years of use from your garden power tool.

What sort of lubricant to use on a hedge trimmer?

A suitable lubricant for a powered hedge trimmer is a 3-in-1 all-purpose oil. However, any grade of engine oil will work just as well. It’s best to oil the blade 30 minutes before use. Then, you can apply the oil with an old rag, brush, or machine oil applicator to restore corrosion protection.

Should you oil hedge trimmer blades after sharpening?

Oiling after sharpening your hedge trimmer is a crucial part of maintenance. Applying a few drops of lubricating oil to the blade ensures that moisture doesn’t affect the hardened steel and cause rust. Additionally, lubrication prevents the moving parts from seizing, keeping the cutting action at optimal performance.

How do you lubricate hedge trimmers?

To lubricate hedge trimmer blades, put a few drops of 3-in-1 oil on the blade and wipe with a clean cloth. Remember to ensure the power tool is unplugged or the battery is removed. Lubricant prevents friction between the blades and prevents excess heat from damaging the blades’ integrity.

How to adjust hedge trimmer blades after sharpening

The hedge trimmer dual-action blade requires the proper alignment to operate efficiently. If the tension on the blades is too much, the trimmer will overwork, overheat, and break down quickly. However, branches will snag if the blades are too loose, and you risk breaking the blade’s teeth.

Use a spanner to adjust the tension bolts that secure the blades. The blades should have a snug fit. If the blade alignment is correct, you should be able to move the blades forward and backward effortlessly—with gloved hands, of course.  


Keeping hedge trimmer blades sharp is a vital maintenance task to extend its lifespan. In addition, sharp blades will result in consistent cutting performance. As a result, you will spend less time and effort in the garden and achieve superior results.