DIY Guide: How to Sharpen A Sling Blade?

This DIY Guide will help you to learn how to sharpen a sling blade easily.

A sling blade is a very useful tool, especially when you have problems with weeds in your garden. However, with use and rust, the blade loses its edge.

For optimal performance, your sling blade must be sharp at all times. Many people often discard their old and dull sling blades, not knowing that with few tools it’s possible to leave them as new.

If there’s a rusty sling blade in some corner of your garage, it’s time to get it out of there. Today you’ll know how to sharpen a sling blade in easy to understand steps.

What is Sling Blade?

A sling blade is a tool used to cut weeds that are too tall. Weeds in gardens absorb nutrients and sunlight that your plants should be absorbing. They also give the place a bad look.

Using a sling blade is very simple. As if it were a pendulum, drop the tool from side to side. Raise your arm as much as you can to apply more energy. The blade cuts every time it hits the weeds at high speed.

Usually, the body of a sling blade includes a shaft, two metal brackets attached to the shaft and a blade. The blade is basically a steel rectangle with waved edges. The waves work like teeth and prevent pieces of weeds from getting stuck.

Step by Step Guide of How to Sharpen A Sling Blade

Sharpening a sling blade is very easy. However, you need the right tools to do it. It’s advisable to use safety equipment such as glasses and gloves to prevent accidents.

Once the minimum safety conditions are guaranteed, you can start working. First of all, make sure you have the following tools on hand:

  • Flat head screwdriver
  • Vise
  • Triangle file
  • Fine grit stone
  • Rotary tool
  • Grinding stone tip

Now you just have to follow these simple steps:

  • Detach the blade from the brackets. To do it you need to use a flat head screwdriver. Remove the screws and nuts on both sides of the blade.
  • Secure the blade to the vise. Be very careful to not apply too much pressure, especially if the blade isn’t completely flat. You could ruin the beveled pattern.
  • Now you can begin to sharpen the blade. You can do it with a triangle file and a fine grit stone or with a rotary tool with a grinding stone tip. Here’s an explanation of how to do in both cases.

With A Triangle File

Gently slide the edges of the file over the slots of the waved pattern. It’s advisable to slide in only one direction to have a uniform sharpness. Make the same movement as many times as necessary until the imperfections disappear.

When you finish sharpening all the waves, it’s time to move on to the next step. Slip a fine grit stone over both waved edges, just as you would with a knife.

With A Rotary Tool

With a rotary tool, the process is much simpler. Using a grinding stone tip, correct all imperfections in each wave. Make sure the tip is small enough to enter the slots.

When finished, use a cylindrical grinding stone tip to sharpen the edges. With circular movements, slide the tip over each wave.

Finally, remove the blade from the vise. Then, secure the blade to the brackets using the screws and nuts you removed at the beginning.

Now your sling blade is ready for duty. Remember that with each use, the blade tends to lose edge. Avoid rubbing with the ground and impacts with rocks and other hard surfaces. This could ruin the edges.

Keep your sling blade in a safe and moisture free place. These types of tools rust very easily.


You no longer need to buy a sling blade every time the blade loses its edge. If you have all the tools at hand, you can extend the lifespan of your sling blade several more years. If you use a hardwood shaft, be careful of the strong impacts that could break it.

Learning to preserve your tools is the best way to save money in the future. Your sling blade can last forever if you follow these valuable tips.

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