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9 Common Brush Hog Blade Questions (With Answers)

9 Common Brush Hog Blade Questions (With Answers)

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A good brush hog blade is the difference between a neatly trimmed field and a heap of torn trees, bushes, and uneven grasses. Some routine maintenance can make sure that your blades function at their best.

Brush hog blades need routine care according to how and how often they get used. Some questions about good care revolve around needs for sharpening, replacing, balancing, cleaning, and the timing and frequency these jobs need to be done.

Here are some answers to common maintenance questions of brush hog blades.

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1. Do Brush Hog Blades Need To Be Sharpened? 

Brush hogs handle the clearing of rough areas with tree saplings, bushes, and tall grass, often over many acres. All of these plants pose varying degrees of wear on brush hog blades. Such areas also have rocks that can nick, crack, and even dislodge the blades. 

Brush hog blades need routine sharpening to operate efficiently. Once they no longer make even cuts, you need to file them to fix the dullness, bending, cutting angles, and some kinds of cracks.

Dull blades tear rather than cut plants. Once sharpened, not only do the blades cut, but they can tolerate rock interactions better. The brush hog will also strain less and so require less power to operate. 

While they may be heavy rotary motors, brush hogs have a simple design that makes the blades easy to remove and sharpen. Even new owners can make the necessary adjustments with commonplace tools.

2. How Often Do You Sharpen Brush Hog Blades? 

Brush hog blades operate by whacking objects with incredible force, so the sharpness of the blades isn’t as critical as it might seem. Some people prefer to replace their blades. Most brush hog users who choose to sharpen the blades of their cutter will generally file or whet every five years. 

You might prefer to sharpen the brush hog blades every spring or after you drive over a few rocks in the field if you use your brush hog a lot. You might also choose to sharpen the blades once you notice the machine is shredding plants rather than cutting them.

Another less common approach is to keep a blunt set for saplings and sharpen when the blades no longer cut the stems. Then you can have another, sharper set for grass so that taller grass gets cut instead of bending over and twisting under your machine (source).

When you sharpen your blades also comes down to what type of blades you have.

Chisel blades, which have teeth on the edges, have a simple rule to judge. Sharp teeth are triangular, but they become rounded over time. So if you see rounded teeth, you know your brush hog will cut better if you sharpen the blades.

Other blades include knife and mulching blades. These need sharpening when you notice they have an uneven sway to their edges, other crookedness, or chipping.

3. How Do You Sharpen Brush Hog Blades? 

Sharpening brush hog blades can be a simple maintenance routine. Depending on what kind of damage your blades have, you’ll have to choose between using a flat file, whetstone, or grinder. Either way, you follow the same general process.

To sharpen brush hog blades:

  1. Park the tractor and brush hog in a flat area.
  2. Raise the mower deck of the brush hog.
  3. Turn off the engine of the brush hog.
  4. Set the parking brake.
  5. Remove the key.
  6. Remove the blade from the cutting head.
  7. Choose a sharpening tool based on the blade damage.
  8. Sharpen the blades.

This process means that you’re avoiding serious injury by turning the engine off. If anything comes up, you don’t want the blades to surprise you and start moving while you handle them. You can also disconnect the spark plug wire to be extra safe.

It’s also easier to properly sharpen the blades after you’ve removed them rather than trying to do the job while they’re attached to the brush hog.

Make sure to put on gloves. You can safely work with metal in case of chipping from its damage in the field.

If you see minor dulling, striking with a flat file or a whetstone will accomplish all the sharpening you need, and you can reattach the blades and get back to clearing your property. Flat files are most effective with bent blades to get the right blade angle. Stroke the file at an up-down position for both sides.

Whetstones come in medium-grain and fine-grain. Position the blade at a 45-degree angle against the whetstone. Then move the blade in an inward-outward direction for both sides of the blade. Use the medium-grain whetstone first and save the fine-grain whetstone for finishing touches.

Severe dulling might need a grinder. Depending on how severely the blade is dulled or worn, you might be better off purchasing a new blade instead of trying to revitalize your current one. 

I want to encourage you to watch this YouTube video on sharpening brush hog blades. This guy takes a lot of pride in his work and really provides some great insight along the way as he walks through the process:

How to sharpen" bush hog" or rotary cutter blades and properly inspect and maintain

4. When Should I Change My Brush Hog Blades? 

Some people prefer to change their blades instead of sharpening them, and the timing has the same reasons as when you sharpen blades.

You should change brush hog blades when your hog starts to fracture stems or twist grass instead of cleaning and cutting them. If you want to be ahead of this stage of dullness and brush hog regularly in areas with rocks, replace your blades every season.

Dullness depends on how often you brush hog and what you’re cutting. If you brush hog a lot, you’ll need to check more frequently. For most users, though, once a year turns out to be plenty. If you have no rocks in the areas you cut, your blades might be fine for decades.

If you see nicks and cracks from rocks, that’s a good sign that you need to replace or file the blades.

Buying a 1/16 edge gets the job done with the right balance of sharpness and bluntness. It’s sharp enough to cut so that the bush stems don’t shred as strips while remaining attached. Yet, it’s blunt enough to tolerate bumps with rocks and chops stems so that the remains aren’t pointy and damage the tractor tires (source).

5. Do Brush Hog Blades Need To Be Balanced?

Sometimes filing will create a weight imbalance on one end of the blade over the other.

Brush hog blades will need to be balanced if you’ve removed the blades either for sharpening or replacement. Blades need evenness to achieve a clean cutting, survive striking rocks, and maintain the health of the brush hog.

Balance for the blades occurs at the cone part, known as a cone balanced, of the blade attachment head.

While they may seem intimidating, brush hogs make things straightforward for owners. All you need are everyday tools to remove and balance blades. 

6. Do Brush Hog Blades Need To Be Cleaned?

Brush hogs travel through rougher terrain than most cutters and naturally will get dirty or collect clutter. 

Brush hog blades need to be cleaned on two occasions. You should do it after every use before you store the brush hog, and you should do it before any sharpening.

In part, it’s good practice to store clean equipment rather than forget, and over the years, the grime builds up. The other reason is that sharpening a clean blade is less effort than doing so through old plant material and layers of dirt.

With a few tools like wrenches, hammers, and screwdrivers, even owners with limited experience can clean their brush hog blades. 

7. How Do You Clean Brush Hog Blades?

Cleaning brush hog blades is a valuable maintenance routine. The more frequent you do it, the better, such as after every day spent cutting a field.

To clean brush hog blades:

  1. Park the tractor and brush hog in a flat area.
  2. Raise the mower deck.
  3. Turn off the engine.
  4. Set the parking brake.
  5. Remove the key.
  6. Remove the brush hog blade from the cutting head.
  7. Remove all the debris on the blades.
  8. Remove grime with soapy water and a rag.
  9. Dry the blades.

After the blades dry, you’re done and can reattach the parts.

This cleaning process means that you’re avoiding detrimental injury by turning the engine off. If anything comes up, the blades cannot accidentally activate while you handle the parts. You can also disconnect the spark plug wire to be extra safe. 

Put on gloves so that you can work with metal. It could’ve chipped edges from its damage in the field.

It’s also easier to wipe down and free the blades of debris after you remove them rather than cleaning them while they’re attached to the brush hog.

A brush with bristles will help you with removing debris. Hard bristles are more effective, but they also can scratch the blades. Soft bristles still get the job done without the risk of contributing damage that rocks do. Soft brushes also can reach more on smasher blades. Damp rags can be helpful with knife and chisel blades.

You can scrub away difficult grime with a soapy, damp rag. Some people hesitate to apply water to brush hog blades because water can find a way to the engine. But if you’re cleaning a blade already separated from the brush hog, you won’t have an issue.

After a solid cleaning, use a dry rag to wipe down the blades. Besides cleaning away from the brush hog, preventing water damage to the engine involves making sure everything is dry before reattaching them. If you store the blades instead of immediately reattaching them, then the moisture can cause rust. Either way, make sure you dry your blades well.

8. How Do You Balance Brush Hog Blades?

Brush hog blades need well-distributed weight and shape to cut cleanly and not strain the brush hog engine. Balance comes from symmetry in the shape and sharpness of opposing blades. For instance, sharpening requires shaving off mass from the metal, thus lightening it.

To balance brush hog blades, you can test one by hanging its center on a nail. If its sides don’t hang evenly to each other, then the blade isn’t even. Then, use a flat-file to sharpen the heavier side until the blade hangs evenly.

Balanced brush hog blades are also safer. They’re less likely to get dislodged when they spin over and strike a rock. They also don’t cut stems so that they end up with a sharp point that can puncture the tires of the brush hog.

9. How Do You Replace Brush Hog Blades?

If you work your brush hog in a harsh landscape, you’ll find that you need to replace the blades at some point. The wear and tear come from fields with many rocks and invading trees and bushes with sizes that test the limits of the cutter.

To replace brush hog blades:

  1. Park the tractor and brush hog in a flat area.
  2. Raise the mower deck of the brush hog.
  3. Turn off the engine.
  4. Set the parking brake.
  5. Remove the key.
  6. Remove the brush hog blade from the cutting head.
  7. Securely attach the new blade.

Then you’ll have replaced the brush hog blades.

This approach means that you’re preventing catastrophic injury by turning the engine off. If anything happens, you’ve removed all possible ways for the blades to surprise you while you work. You can also disconnect the spark plug wire to be extra safe.

Put on gloves so that you can work with metal, safe from chipped edges from damage in the field (source).


A good brush hog blade is key to equipment longevity and a clean cutting of fields. Without good blades, the brush hog can leave trails of partially-shredded bushes and grass. 

Routine care that brings the best out of your blades revolves around the timing and frequency of these maintenance actions. The most important care choices for the blades are sharpening, balancing, cleaning, and outright replacing them. 

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Paul Brown
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