Sharpening Bush Hog Blades – 3 Easy Methods

Sharpening Bush Hog Blades

Bush hogs are the perfect tools to whack through dense plant growth. They attach to the mower deck and clear bushes that may inhibit the lawn grass.

Unfortunately, there’s common confusion about sharpening bush hog blades. Additionally, many homeowners struggle to sharpen the blades properly.

This guide explains everything you need to know about sharpening bush hog blades.

Read: Can you mow while pregnant?

What are Bush Hog Blades?

Brush hogs, also known as Bush Hogs (the biggest brush hog brand name), are multi-functional rotary mower blades attached to the back of a farm tractor.

You don’t attach them rigidly like a mower blade. Instead, smaller ones mount to the three-point hitch while larger ones attach to the drawbar, so the hydraulic system raises and lowers the head as necessary.

A small bush hog can pass 4-5 feet, while larger ones cover up to 15 feet. Extra-large brush hog blades are only found on large tractors.

How Do Bush Hog Blades Work?

Brush hog blades are purpose-built to knock down vegetation and weeds to create a more even lawn or garden.

It’s also ideal for trimming weeds around your property, mowing grazing paddocks, and clearing hayfields that have gotten too mature.

The “rough-cut” machines easily cut down mature weeds, grasses, and small bushes, a task you cannot accomplish with the traditional lawn mower blade.

Related: Grading scraper vs box scraper

Are you Supposed to Sharpen Bush Hog Blades?

Yes, you should sharpen bush hog blades. The blades handle many rough projects, from tree saplings to bushes and tall grass.

Thus they become blunt quickly. Moreover, rocky or rough terrain can nick, crack, or dislodge the blades. Therefore, routine sharpening is very important.

Sharp blades enable faster mowing, whereas dull blades tear the grass. Moreover, sharpening fixes misaligned cutting angles and cracks on the blade.

Fortunately, the blades are easy to remove and sharpen. More importantly, you don’t need special tools to sharpen brush hog blades.

See: How to sharpen an edger blade?

How Often Should You Sharpen Brush Hog Blades?

Most brush hog users prefer to sharpen or whet their blades every five years. We recommend more frequent sharpening, ideally every spring if you use the brush hog a lot.

Signs of dull Bush Hog blades

Alternatively, you can sharpen your blades when you notice significant dulling or chipping. One of the signs of a dull blade is shredding. It rips plants rather than slicing them.

The blade is also extremely dull if you notice uncut bush patches on the lawn. Finally, the sharpening frequency depends on the type of blade.

Chisel blades with teeth on the edges are easy to judge – sharp teeth are triangular, while dull teeth are rounder.

Meanwhile, knife-edge and mulching lawn mower blades are ripe for sharpening if the edges are irregular, crooked, or chipped.

Bush hog blade sharpener options

The best way to sharpen a brush hog blade is using an angle grinder or bench grinder. Both powerful tools work exceptionally fast and guarantee great results if you follow the manufacturer’s guidelines.

  1. Rotary Blade Sharpener: A rotary blade sharpener is a handheld tool specifically designed for sharpening rotary cutter blades, including Bush Hog blades. It typically features a grinding stone or abrasive material that helps restore the blade’s cutting edge.
  2. Bench Grinder: A bench grinder is a stationary tool with grinding wheels that can sharpen various blades, including Bush Hog blades. It provides a stable platform for precise sharpening and allows you to adjust the grinding angle as needed.
  3. File or Whetstone: For those who prefer manual sharpening, a file or whetstone can sharpen Bush Hog blades. These tools require skill and patience but can effectively restore the blade’s sharpness.

How to Sharpen Bush Hog Blades

The three main ways to sharpen a bush hog blade are by using an angle grinder, bench grinder, or a sharpener file. Begin by detaching the blade from the lawn mower.

Then clean it with a wire brush, pressure wash, and allow it to dry before sharpening. Most homeowners sharpen or whet their brush hogs every five years.

1. How to sharpen bush hog blades using an angle grinder

The following is a step-by-step guide to sharpen your brush hog blade using an angle grinder and a grinding stone disk.

  1. Wear safety equipment, including a protective face mask and hand gloves.
  2. Clean the blade to remove soil and debris. We recommend scrubbing it with a wire brush.
  3. Secure the blade to a workbench or table with a vice or clamps.
  4. Select the right grinding stone disc. Alternatively, use a diamond grinding wheel.
  5. Attach the grinding disc to the angle grinder and secure it tightly to avoid slipping.
  6. Plug in the angle grinder and align it with the brush hog blade at the factory-recommended angle.
  7. Start the angle grinder and make several passes along the blade edge in smooth motions. Don’t round off the blade corners, as this is where most of the cutting happens.
  8. When done, remove the blade from the vice and flip it over to sharpen the reverse edge.

2. How to sharpen bush hog blades using a bench grinder

Sharpening brush hog blades using a bench grinder is similar to the angle grinder process, except that a bench grinder is fixed to the workbench.

Here’s how to proceed;

  1. Wear protective gear, including eye goggles to protect your eyes from sparks and hand gloves to protect your hands from heat.
  2. Remove and clean the blade. Unfortunately, you cannot sharpen the blade with a bench grinder without removing it.
  3. Load the bench grinder with the appropriate grinding wheel, such as the Norton White Aluminum Oxide grinding wheel.
  4. Plug the bench grinder into the power outlet and push the start button.
  5. Hold the blade at 45 degrees (or the factory-recommended angle) and lightly pass the cutting edge against the rotating grinder wheel. Again, don’t round off the corners. Maintain even pressure for an evenly sharpened blade.
  6. When done, flip the blade to sharpen the opposite edge.

3. How to sharpen bush hog blades using a sharpener file

If you cannot readily access an angle or bench grinder, a sharpening file will do. Here’s how to sharpen your brush hog blade using a sharpening file;

  1. Secure the blade on the workbench using a vice or clamps.
  2. Hold a 12-inch or 14-inch flat or bastard mill file against the blade.
  3. Adjust the file angle to match the original factory bevel setting. It’s typically 40-45 degrees.
  4. Begin sharpening by pushing the file against the blade away from your body. You should feel the file grinding away material from the blade.
  5. Make repeated passes as you work your way from one end of the blade to the other.
  6. Reposition the blade to sharpen the opposite edge.
  7. File away the burrs using gentle strokes.

Best practices for sharpening Bush Hog blades

Bush Hog Blade Sharpening Angle

Does the blade sharpening angle matter? Yes, it does.

You should sharpen bush hog blades at a 45-degree angle, though some blades are sharpened at 40 degrees. The idea is to match the original cutting edge.

Remember that sharper angles result in sharper blades, which cut more easily but dull faster. Meanwhile, wider angles produce less sharp blades, which dull less fast.

How to Remove Bush Hog Blades

Removing brush hog blades is easy. First, park the lawn mower in a flat place in the shade and switch off the engine.

Then tilt the cutting deck to access the underside. You’ll notice that a center bolt holds the blade to the deck.

Wearing proper safety equipment, including eye goggles and hand gloves, loosen the bolt using an impact wrench. Then remove the bolt and washer and gently remove the blade.

Can You Sharpen Bush Hog Blades Without Removing Them?

Yes, you can sharpen blades without removing them. Indeed, many owners are excited to skip the blade removal part.

However, Bush Hog recommends removing the blade before sharpening it. It allows you to sharpen the blade equally along the length.

In addition, It gives you a chance to balance the blade for even cuts.

When to Replace Brush Hog Blades

It’s time to replace your bush hog blade if the blade fractures plant stems and twists grass rather than slicing the stems.

This is one of the reasons some homeowners replace their bush hog blades every season. A new blade arrives factory-sharpened and easily lasts a season without resharpening.

Before replacing, you need to learn how to measure bush hog blades for references;

  1. Ensure safety: Before measuring, ensure the equipment is turned off and take necessary safety precautions.
  2. Measure blade length: Use a measuring tape or ruler to determine the length of the blade from one end to the other. Measure along the cutting edge.
  3. Measure blade width: Measure the width of the blade, which is the distance from the cutting edge to the opposite side.
  4. Note blade hole diameter: Measure the diameter of the center hole in the blade. This measurement is important for compatibility with the Bush Hog equipment.
  5. Record measurements: When purchasing or replacing Bush Hog blades, note the measurements for reference.

Now that you have your new blade, it’s time to install it

To replace the bush hog blade, proceed as follows;

  1. Park the lawn mower in a flat area.
  2. Turn off the mower engine, set the parking brake, and remove the key.
  3. Remove the old blade from the cutting head.
  4. Install the new blade.

Read: How soon can you walk on new grass?

How to make a bush hog cut better

Here are three tips to help you improve the cutting performance of your Bush Hog

Ensure Proper Blade Sharpening

Sharp blades are essential for efficient and clean cutting. Regularly inspect them for dullness or damage. If needed, use appropriate sharpening tools like a rotary blade sharpener or bench grinder.

Maintain the correct cutting angle and sharpen both sides evenly. Dull blades can cause uneven cutting, increased resistance, and strain on the equipment.

Adjust Cutting Height and Overlap

Properly adjust cutting height and overlap to impact cutting quality significantly. Set the height according to desired vegetation and terrain.

Start with a higher cutting height and gradually lower it for the desired result. Adjust overlap to ensure complete coverage without leaving uncut areas or stressing the equipment.

Maintain Optimal Ground Speed

Maintain an appropriate ground speed for optimal cutting results.

Operating too fast can lead to missed vegetation or uneven cutting while operating too slow strains the equipment and hampers cutting performance. Find a speed that engages the blades effectively while maintaining control and safety.

Bush hog maintenance

Tips for maintaining sharp Bush Hog blades;

  1. Regular Inspections: Check the blades for dullness, damage, or wear. Catch issues early to prevent further damage.
  2. Sharpening Schedule: Establish a regular routine based on usage and cutting conditions. Sharpen at least once per season or more if needed.
  3. Proper Sharpening Technique: Follow the manufacturer’s recommended technique. Use suitable tools and maintain the correct angle for effective sharpening.
  4. Blade Balancing: Check balance after sharpening. Imbalanced blades cause vibrations and equipment damage. Balance by removing material from the heavier side.
  5. Lubrication: Apply a thin coat of lubricant or rust inhibitor after sharpening to protect against corrosion and maintain sharpness.
  6. Cleanliness: Keep blades clean from debris and clippings. Remove buildup that affects cutting performance and dulls the blades.
  7. Safe Handling: Follow safety precautions. Use protective gear, turn off equipment, and secure it before maintenance tasks.

And how does a bush hog compare to other options? To answer that question, here is a comprehensive guide comparing Flail mower vs Bush Hog to assist you in making an informed decision for your specific land clearing or mowing needs.

Common Blade Sharpening Mistakes to Avoid

Improper Angle

Sharpening blades at the wrong angle can result in inefficient cutting and premature wear.

  • Tips:
    • Refer to the manufacturer’s guidelines or manual to determine the recommended sharpening angle for your specific Bush Hog model.
    • Use a sharpening tool, such as a rotary blade sharpener or bench grinder, to consistently maintain the correct angle.
    • Double-check the angle during the sharpening process to ensure accuracy.

Inconsistent Sharpness

Inconsistent sharpness across the cutting edge leads to uneven cutting and subpar performance.

  • Tips:
    • Carefully sharpen each section of the blade’s cutting edge evenly.
    • Use consistent pressure and strokes while sharpening to achieve a uniform sharpness.
    • Regularly inspect the blade during sharpening, ensuring no areas are overlooked.

Neglecting Balance

Ignoring blade balance can result in equipment vibrations, damage, and reduced cutting quality.

  • Tips:
    • After sharpening the blade, check its balance by placing it on a balancer or a similar tool.
    • If the blade is imbalanced, carefully remove material from the heavier side until it is balanced.
    • Use caution and follow safety guidelines while adjusting the blade’s balance.


Are bush hog blades supposed to be loose?

No, Bush Hog blades should not be loose. Properly installed blades should be securely tightened to the specified torque. Loose blades can cause inefficient cutting, vibration, and potential damage to the equipment. Regularly inspect and ensure the blades are securely fastened according to the manufacturer’s guidelines for optimal performance and safety.

What’s the best STIHL brush cutter blade sharpening tool?

STIHL recommends various files and filing gauges to help you achieve optimum brush cutter blade sharpness. These include triangular sharpening files, flat files, and mill saw files. You can also purchase a sharpening template for greater accuracy. Consult the company before committing your money.

See: Meg mo blades problems

Can you sharpen the blades on a rotary cutter?

Yes, you can sharpen rotary cutter blades. Angle grinders and bench grinders are the best tools for the trade. However, you can also use a sharpening file to sharpen rotary cutter blades. Remember to follow the factory-recommended sharpening angle. Also, clean the blade before sharpening.

How sharp should bush hog blades be?

Ideally, your brush hog blades should be sharp enough to cut bush stems without shredding. However, you don’t want a razor-sharp edge. First, overly sharp blades dull fast. Additionally, a very sharp blade can create spikes that may go through a tire or someone’s foot.

Interesting read: How Sharp Should Lawn Mower Blades Be?

Are bush hog blades universal?

No, Bush Hog blades are not universal. They are designed specifically for Bush Hog equipment, with unique dimensions and hole patterns. It is crucial to select blades that are compatible with your specific Bush Hog model to ensure proper fit and optimal performance.

Final thoughts on sharpening bush hog blades

Bush hog blades, formally known as brush hog blades, are easy to sharpen. Detach the blade from the mower deck, secure it to a standard workbench using a vice, and sharpen with an angle grinder or file sharpener.

Alternatively, sharpen it with a bench grinder. Consult your owner’s manual for the sharpening angle.