Instructions for Changing & Honing Your Push Mower Blades

mower blades

Before attempting any diagnosis, repairs, or use of the equipment, be sure to read and fully understand any safety instructions included in the owner’s manual. If you are unsure about how to proceed or if you lack the necessary expertise or experience, you should seek the assistance of a professional.

When Should You Replace Your Lawn Mower Blades?

Changing the blades on a lawnmower once a year is recommended. If your blades are constantly getting dragged through the mud and gravel, you should replace them more often.

During the annual maintenance you perform on your mower, you should also replace the blades.

You should sharpen the old blades and keep them on hand in case you damage your new blades during mowing and need an extra pair to finish the task, provided that the old blades are not damaged or too worn.

Is There a Recommended Routine for Sharpening Lawnmower Blades?

When your mower has been in use for 25 hours, sharpen the blades. Mower blades need to be sharpened at least twice a year for the typical homeowner.

Again, working in sandy and gravelly environments will require more frequent sharpening of your blades to provide a clean cut.

Should You Sharpen New Blades?

Sharpening new mower blades is not necessary before installing them on a mower.

This is due to the fact that blades are sharpened and painted by the manufacturer at the same time. Cutting with it will eventually remove the paint from the blade.

Look for Signs of Excessive Wear and Damage on the Mower Blade

The quality of the cut made by a mower might be diminished if its blade is worn out or otherwise damaged. If your lawnmower is giving you a poor or uneven cut, it may be time to inspect the blades.

Wearing a Sail Blade

The high side of the blade is called the sail. Sails can wear down over time from having dirt sucked under the deck.

When the sail is in poor condition, it cannot draw enough air to the deck to create a suction that will hold the grass in place while the blade cuts it cleanly.

If the sail of your mower blade is thinner than the rest of the blade, you need to get a new one.

Cracks and Gouges

The quality of your cuts will suffer if your mower blade has any nicks in the cutting edge. In most cases, sharpening the blade will fix minor damage like chips in the edge. In areas with more severe nicks and gouges, you should get a new mower blade.

Curved Blade

Your mower’s cutting ability will suffer if the blade is curved. When striking a hard surface, such as a tree root or rock, a blade can flex.

If you suspect a bent mower blade, it is preferable to compare it to a brand new one. Remove your blade and have it inspected by a dealer if you don’t have access to a replacement.

You should never try to utilize a blade that has been bent. The structural integrity of the blade is weakened as a result.

Split Blade

If you find a broken mower blade, you need to replace it immediately. A damaged blade spinning at high speeds beneath your mower deck can easily break off and launch itself away from the machine. This poses a danger to nearby humans, animals, and property.

Factors That Hasten the Blade’s Wear and Damage

Before you start mowing, it’s a good idea to take a stroll around your lawn and pick up anything that could get in the way of your mower or cause it damage. Things like pebbles, sticks, and toys all qualify.

The only way to prevent the blades from wearing down too quickly from sand and debris is to have a denser covering of grass on your lawn, which will prevent as much soil from being sucked into the mower deck.

Some lawn chemicals that promote grass growth can eat away at your mower’s blades and deck. The blades should be taken out and cleaned on a regular basis.

Because of the corrosion, your blades may bond to the deck components, making removal extremely difficult. Keeping the blades out and back in the rotors on a regular basis will lessen the likelihood of this happening.

Taking Apart and Reassembling Your Lawnmower Blades

Gather Equipments:

  • Socket wrench
  • Work gloves
  • Safety Glasses
  • Torque Wrench
  • Block of Wood

Take Out the Blade of Your Mower

  • Make sure the spark plug boot is detached and the key is out of the mower if it has one. If you need to handle the mower blades, be sure you have on a sturdy pair of gloves.
  • Turn the mower on its side and get it ready: Before laying your mower on its side, make sure the fuel valve is in the off position to prevent gas from leaking. Flip the mower over so the air filter is on the top.
  • Take off the blade nuts: When removing the nuts and washers with a socket wrench, make sure the blades can’t turn by inserting a block of wood between the blade and the deck housing.
  • Take out your lawnmower blades

Put the Blade on Your Lawnmower

  • Before installing new blades, make sure the space under your deck where they mount is clean. Make sure your resharpened blades are balanced before using them again. Please see the “Balanced Blade” section for more information.
  • Put the upper and lower blades in place, then use the bolts and washers to tighten them. Be sure the washer’s concave side is facing the blade.
  • Use a torque wrench to secure the bolts in accordance with the manufacturer’s recommendations given in the user handbook. Be careful to apply the proper amount of torque so that the blade stays securely attached to the mower and nobody gets hurt. Keep the blade from spinning as you tighten the bolt by placing a block of wood under it.

DIY Lawnmower Blade Honing Instructions

Mower blades can be sharpened by the owner, saving both time and money. How much cash you can save while sharpening your knife depends on the strategy you use.

It’s not always worthwhile to take on a project by yourself. You need to make a decision based on your own needs. If you’d like to sharpen your own mower blade, consider the advice below.

Gather the necessary equipments

  • 10″ flat metal file, drill-powered blade sharpener, or disc grinder
  • A vice to hold the blade in place
  • Blade balancer or nail on the wall
  • Rags
  • Wire Brush
  • Safety glasses
  • Work gloves

Maintaining Clean Lawnmower Blades

Wear protective equipment like gloves and goggles. Remove grime from your mower’s cutting edges with a damp towel. For more tenacious accumulation, a wire brush may be necessary.

Mower Blade Security

Put your knife in a vice to make sure it doesn’t move as you sharpen it. When you’re done with one side of the blade, put it in the vice and flip it over to sharpen the other side.

Sharpening a blade with a File or Grinder

File down with metal to sharpen

  • You can achieve this by filing in one direction at an angle.
  • When filing, avoid using a sawing action.
  • Once one side of the blade is sharpened to perfection, it should be reversed in the vice to be sharpened.

Use a sharpener that is driven by a drill to hone your blade

  • Activate the blade sharpening drill.
  • Align the sharpener’s flat guide with the blade’s flat part, slotting the cutting edge into the bevel.
  • The blade edge is sharpened by moving the sharpener up and down its length.
  • When one side of the blade is smooth and sharp, you can reverse it in the vice and sharpen it in the same way.

Hone with a bench or angle grinder

  • Keep the angle grinder at a right angle to the cutting edge. If the blade has any nicks or rough places, you can smooth them out by running a grinder along its length. The metal can be removed more evenly if you keep the grinder moving as you work.
  • Once you get a smooth edge on one side, flip the blade over, put it in a vice, and sharpen the other side the same way.

Balancing a Lawnmower Blade

Before putting your mower blade back on, make sure it is properly balanced. The crankshaft could be damaged by vibration if this isn’t done.

When the blade’s weight is distributed evenly on both sides, we say that it is balanced. Check the blade’s balance with a blade balancer.

If you don’t have a blade balancer, just hammer a nail into the wall so that its head is between three-quarters and one inch from the surface. Put the nail in the blade’s center.

The blade should be perpendicular to the nail head as it rests there. If it doesn’t, you can trim the metal off the blade’s bottom edge until it’s flush with the upper edge.

When Should You Have Your Lawnmower Blade Sharpened by a Professional?

If you are unsure of your ability to sharpen or balance a blade, it is best to see an expert. Worn or unbalanced blades can cause additional wear and tear on your crankshaft and engine.

Even though I own the equipment necessary to do it myself, I have always preferred to get my blades sharpened by the local lawn mower dealer. They basically give the blade a better, cleaner edge than I can.

For the following reasons, you may decide to have a professional sharpen your blades:

  • Sharpening the blade yourself is the safer alternative.
  • In many cases, having a blade sharpened will save you money over buying a new one.
  • Large nicks and gouges in the steel can be removed from mower blades by having them ground down by a specialist.
  • The razor is well balanced. The vibration and wear and tear on your mower will be minimized.