Depending on the brand you have, lawnmowers can have up to seven different blade types. There are blades, especially for mulching, detaching, regular mowing, and many other tasks. When they are new, they are really sharp to perform their cutting task. However, the blades get dull over time by working in harsh environments full of dirt, debris, and rough-tough grass. After a season, typically 30 to 40-hour action, the blades require sharpening. The blades can be sharpened using simple tools like a grinder, Dremel, or even a hand file. But the blades can be sharpened a maximum of 4 to 5 times. After this, you may use the blade’s metal for other purposes as it is still usable. This article will take you through the criteria to check your blade condition and what to do with them, depending on the case.
What to do with old lawnmower blades? These are the four best options:
- First step: Check the old blades properly
- Option 1: Sharpening by hand or a file
- Option 2: Sharpening by grinder and Dremel
- Option 3: Turn them into knives or an other tool
- Option 4: Usage in the Electrolysis process

Lawnmower blades are located at the bottom of your machine. No matter how strong the blades are, they will all get dull. Tools like a grinder or a Dremel chip off the rough metal, even the profile, to give you a sharp surface. In case the mower blades are not in shape to be reused, you can always use the blade metal to create some sharp knives. Moreover, the blade is made from good quality and pure iron or steel usually. The blade can be used as an agent in an electrolysis process. Or, you can sell the old blades. This article will look at some of the things you can do with old mower blades.
What can you do with old lawnmower blades:
We will look into more detail about the different things you can do with an old Lawnmower blade. Before deciding what to do with it, you first have to check the condition.
● Step 1: Check the old blades properly:
Lawnmower blades frequently wear out after 30-40 hours of work. Depending on your situation, this is after each season. One can always sharpen them, but eventually, they reach a point where replacement is unavoidable to ensure smooth operation. The blades can get dull, cracked, or uneven due to the environment’s dirt and debris. Moreover, cutting drier and harder grass is more deteriorating for their health.
To check the blades’ condition, you will have to remove them by simply loosening the nut. Clamp the blade on a bench vise and examine them carefully for the following points:
- How often is it sharpened: It would help if you always keep a pad to note down the number of times the blades have been serviced. If it exceeds 4 to 5 times, you need to use a new set too for a superb quality blade. But this 4 to 5 times is not a rigid boundary. It depends on many factors, like how strong the metal is, how much did you take off during earlier sharpening and the type of previous damage.
- Minor cracks and scratches: If there are minor cracks and scratches on your old mower blade, you can still sharpen them again with basic machine tools.
- Broken: If the old mower blade is broken or chipped off at parts in a way it can’t be reused, you can use the blade for entirely different purposes.
Depending on the examination, you can classify the old blade into two categories:
- It can still be sharpened
- It cannot be sharpened
● Step 2. Sharpen the blades with hands or a file
For category 1 mower blades, the most basic method to sharpen the mower blades one more time is by hand. You can always use a simple rough file to chip off the rough metal. The file cuts in the forward stroke. So, by gently holding the 10 inches file, give regular 15-20 thrusts to scrap the rough surface. A sharp, clearer surface will be the indication of sharp metal. The mower blades are made from relatively softer metals that can you can file easily. File along the blade edge to develop the blade profile.
You can also use a sharpening stone to perform the same task. These are readily available and mostly used for the knives sharpening. The only difference between a file’s and a sharpening stone’s operation is the direction of the angle at which you grab it to sharpen your blade. This stone can be used in both forward and backward strokes, unlike files. It does some sharpening but is more operational in smoothening and polishing the blade surface.
Similarly, you can use a sharpening rod to do the same. However, most commonly, it is used along crevices and the rounds of the blade edge.
● Step 3. Sharpening by Grinder and Dremel
For the category 1 blade, you can also use mechanical tools like the grinder or a Dremel. Adjust the angle grinder with a grinding stone disk, if not previously in place. It would be best if you used safety goggles and gloves while sharpening the blades. In the same way as a file, keeping an angle of 20-30 degrees with the blade surface, you can scrub off the dull surface. Grinders are quite fast in operation compared to a file, but they are also very sharp, so be careful with them. Developing the blade edge profile is tricky. A sharpening stone is probably a be a more straightforward tool for that.
Similarly, you can use a Dremel to create the blade edge profile, smoothen the surface and remove any scratches or cracks. Set the speed to around 2500 rpm, a medium setting. Run it along the blade edge and create a smooth surface.
● Step 4. Turn them into a knife or an other tool
For a category 2 blade, you can use the old blade to create some other tools. The simplest one is a knife. The type of knife you want depends on you totally as the mower blade has a fine metal. It can be a knife for chopping, a simple backyard knife, a pocket knife, or even a kitchen knife. The procedure for all is simple.
You need some basic tools to finish the job:
- Heating source
- Grinder or hacksaw
- Steel pliers
- Hammer
Just decide which type of knife shape you want; mark that shape with some paint or wall chalk. Now, heat the metal red hot and hold it with a set of pliers. Gently place the hot blade on a smooth, even ground. With the help of a grinder or powered hacksaw, cut a rough desired profile out of the blade metal. Let it cool naturally in the air. Now, you need to develop the sharp profile and base of the knife.
The blade part of the knife is from the old mower blade part. So, by using a simple file or angle grinder, you can sharpen the edges for a knife. A knife has to be thin, so you will have more work to do on the surface. Now, you need a good piece of wood to fix on the blade base for the base. The wood piece needs to be tight, so you can also add in a mix of adhesives or glue to hold the blade in place.
As a final step, heat the knife till it is red hot and immediately dip it in water. This process will help make the knife-edge sharper and stronger. The brittle nature increases, but that is not a major concern for a knife. It still is quite strong.
● Step 5. Usage in Electrolysis process:
Similarly, old mower blades can be used in the electrolysis process too. Electrolysis is the process of quoting a metal surface over another metal to increase its life and preserve its surface. An old lawnmower blade can be used as a sacrificial metal for this task. An electrolytic tank is commonly used for removing rust from surfaces. You can use a mower blade surface in conjunction with your old mechanical tools like wrenches, watches, or pliers. By dipping them in an electrolytic fluid and under the current force, you will notice your tools getting clean at the blade metal’s cost, getting deposits on its surface. The deposits shift from one electrode to the other. This is a similar process to gold plating and can be done easily at home.
Frequently asked questions
1. How do I remove my old lawnmower blades?
It would be best if you took out the nut at the center of the blade through a socket wrench; however, it may be stuck. So, spray the nut with penetrating lubricant like WD-40 and wait few minutes if the nut proves challenging to move. If the blade rotates while removing the nut, clamp a piece of wood to the lawnmower’s underside with C-clamps’ help to prevent the blade from rotating while you are working on it. Then, you can loosen the nut with the wrench.
2. How can I dispose of my old lawnmower blades?
As described in the article, you can do many things with old lawnmower blades. But if they are beyond that point, you need to dispose of them. You must be careful with that as they may cut someone’s hand if improperly thrown away. You can:
- Sell them to trade wanderers who buy old scrap metals.
- Give them away in junkyards.
- If you have to throw them in a bin, you must cover them entirely with a few layers of pieces of clothes. Then, label the package and let the waste-collecting men know about it.
3. What is the typical life of a lawnmower blade?
Lawnmower blades typically last 30-40 hours of routine use, after which they must be sharpened. If they are used excessively in a rougher environment, the time limit reduces. The blades can be sharpened a max of 4-5 times. If you keep on sharpening them further, you will damage your mower, and there is even a chance of them breaking mid-process.
Final remarks:
Lawnmowers are machines that work on the force of their sturdy blades. These hard and strong tools also have a life after which they require sharpening and a tune-up. Unlike all other tools, lawnmower blades are special because even after their service life is complete, they can be used in several ways. Most commonly, their converted use as knives and sacrificial knives is quite common and easy to exploit. We hope that you get some insight regarding what to do with your old lawnmower blades from this article.