How To Sharpen Lawn Mower Blades With A Grinder?

How To Sharpen Lawn Mower Blades With A Grinder?

We all know what it’s like to try and mow the grass with inadequate blades. Regularly inspecting your lawn mower blades will help ensure they stay sharp. If they’re looking worn, you’ll want to replace them.

A good rule of thumb is to sharpen your blades before every season, and after about 25 hours of use. If your lawn isn’t recovering well after mowing it could mean that your mower blade needs sharpening more effectively. 

You might notice dents or nicks in your mower blades. These are clues that your blades aren’t sharp enough. 

Your grass will grow unevenly if your blades aren’ t sharp enough and willlook unsightly. You might see brown, frayed grass edges and grass blades that look like they were cut with a knife.

Let’s look at a step by step guide. To help prevent that happening. 

Step 1 (Gather Materials)

Using the correct tool for the job makes the task of sharpening blades easier, gather together the following:

  • A wrench set 
  • A piece of wood  – needed to hold the blade steady while using an angle grinder.
  • Clamping devices  – needed to keep the blade still while grinding the edge. 
  • A plastic bag  – useful to catch any debris. 
  • A wire brush  – will help remove any rust and give the blade a nice shine. 
  • andpaper  – to smooth out any rough spots.

Step 2 (Clean The Blades)

Firstly, you should remove and clean the blades.  Wear gloves and eye protection when removing the blade. 

Drain the fuel tank and lift the engine block out of the engine compartment. Remove the spark plug wire harness and the distributor cap. Locate the bolt that secures the mower blade to your lawn tractor.

Loosen the bolt using a socket or wrench. Once the bolt is loose, pull the blade out of the motor. Take note of the location of the screw holes on the back of the blade. These will help you reattach the blade.

Adjust the angle grinder with an abrasive grinding wheel. Clean all the dust and debris from the grinding surface using a stiff wire brush. Use a polishing pad with diamond particles on the backside.

Wipe down the blade with a clean towel or paper towel.

Step 3 (Use The Grinder)

Step 3 (Use The Grinder)

Ensure you wear protective goggles when working with the tool.

Now hold a grinder above the blade, so that it is at an angle with the cutting edge, and turn it on. First, start grinding the edge, pushing the grinder towards the inside.

Turn the grinder around and grind the other side of the blade. Grind the middle of the blade first, then the edges. You will notice that the blade gets smoother and sharper when you grind the center.

To avoid cracking the blade, make sure that your grinder is angled correctly. If you feel like there is something wrong with the grinder, stop using it immediately!

This step is done to sharpe the edge and set the corner in proper shape. Align the angle grinder with the blade’ s angle from the inside. Then gently push the grinding wheel towards the cutting tip.

Carry out the process along the entire length. The result will be a sharper, finer blade that has an established cutting edge.

How Sharp?

A lawnmower blade should be aggressively sharp, yet not as sharp as a knife’s edge. You should be able to touch it with your hand without cutting yourself.

If you were to try to use a blade that is too sharp, it will tend to roll over, causing damage to the blade. Additionally, if you were to use a blade that was too sharp it will wear out sooner, requiring more frequent sharpening.

Make sure your lawn mower blades are always turned off before performing any maintenance.

Adjusting The Blade

As well as sharpening the blade you should also make sure the blade is balanced. You can check the balance yourself by following these steps:

1) Remove the blade from the mower.

2) Hold the blade horizontally, away from you. Insert the screwdriver tip through a hole in the blade. Make sure the blade is balanced on the tip. Hold the blade horizontally, then slowly release your grip.

You will see the blade fall if it is not balanced. Remove any excess metal and test again.

A blade balancer is an important tool in maintaining your lawn mower. It is typically a cone shaped tool that has a spindel for the blade. When you spin the spindle, the blade spins around the spindle and creates a cone shape.

If the cone is symmetrical, then the blade is balanced. If the cone isn’t symmetrical, then the blades needs to be adjusted.

Reinstalling The Blade 

Reattach the blade to the shaft.Use your hand tools to loosen the bolt. Make sure the wheel is secured properly. Tighten the bolts if necessary. Connect the battery and then fill the tank.

Remove all debris from around the mower. Start the engine and check to see if the mower runs smoothly. If there are any issues, check to make sure you did everything correctly.

Maintaining The Grinder 

You should also inspect the tool to see if it looks like it might be damaged. There may be a loose connection, a broken part, or even a cracked housing.

Don’t just assume that the tool is safe because it still works and always remember that tools can cause serious injury or death.

Whether you use bench grinders or die grinders or angle grinders, most of these inspections will be universal. These inspections are important because if any of these parts are broken, then your grinder won’t work properly.

Some of these inspections include checking for: 

  • Grinding bowl for cracks
  • Motor for overheating or seizing
  • Spindle for cracks
  • Bearings for wear
  • Grinding wheel for chips and cracks
  • Cutterhead for cracks and the cutting edge for chips and cracks.

In Summary 

As summer approaches we want neat and nicely mown lawns so maintaining lawn mown blades is crucial to achieve this. 

Ben Jones

When it comes to selecting the right tool for the job there are some important factors that you have to consider. I hope by sharing some of my knowledge I'll be able to educate you on a range of grinders so you can get the job done.

Recent Posts