First, thanks to Ken S for starting this section and I hope it will help others.
I have been asked a couple of times to sharpen lawn mower blades and was wondering is anyone has experience in grit selection. I have both the SG-250 and DF-250 and was wondering if I could just use the SG-250 with the rough grit and no honing as its just cutting grass and docent need to be refined? I have watched a couple of videos and pretty much all people use a grinder which I thought would effect the temper of the edge which, again may be OK as its only cutting grass.
Thanks
I think something to consider when sharpening things designed to spin, is the balance of it.
I've never sharpened lawnmower blades before, but I have sharpened a giant 35cm deli meat slicer blade. I was very mindful to keep the sharpening as even as possible around the entire circumference, and waiting on any complaints/feedback from the customer.
I also have researched about balancing the lawnmower after sharpening and there are a number of balancers (I have already ordered one) that helps you balance the blade during the sharpening process. An unbalanced blade can and over time, will damage the shaft and bearings over time so balancing is very important.
Lawnmower blades are very forgiving and any sharpening will be infinitely better than how they come from the factory. I have typically used an angle grinder in the past. However a flat single cut file will produce as fine an edge as you will ever need. I would not even bother with the tormek to be honest.
I use a machinist's hand file. It works fine.
Go to allamericansharpener.com if you want to sharpen your mower blades. This product is fantastic.
Quote from: John Hancock Sr on February 19, 2026, 04:20:09 AMLawnmower blades are very forgiving and any sharpening will be infinitely better than how they come from the factory. I have typically used an angle grinder in the past. However a flat single cut file will produce as fine an edge as you will ever need. I would not even bother with the tormek to be honest.
I use an angle grinder with the flappy sanding pad for my mower blades. A drift punch clamped horizontally in the vice provides a nice balancing reference for the blades. If I don't feel like breaking out the angle grinder, I use a file.
I think using the Tormek on lawn mower blades is overkill.
A few strokes on a belt sander do wonders for a lawnmower blade, in less time than is necessary to setup the Tormek. And the Tormek will remove metal much slower than the belt sander, especially on a thick blade.
I used the SG wheel and measured both ends to ensure the sharpened blade was evenly ground and balanced. My neighbour was happy with the result commenting on how well it cut his grass. On a side note, I honed the blade, my logic is a bur could shorten the sharpness life.
I believe that whatever burr is still here after sharpening will be taken care of by the grass itself, and a thick branch or loose stone will nick the blade no matter what.
The wear on the SG stone and the hassle of setting up the Tormek for lawnmower blades make it ill suited to the task, especially when one includes the time required to true the SG afterwards.
The system mentioned by GeoBoy makes much sense for people who do that on a regular basis and for people who do that only occasionally, a belt sander, bench grinder or angle grinder will work better and faster.
I bought the SVD-110 Tool Rest and have been using it with the DF 250 to sharpen mower blades and its quick and really precise, no truing and I use the marker method (most blades are coming up between 35° - 40°.
If the blade is uneven, I use the KJ45 with no problem.
Quote from: Rossy66 on April 15, 2026, 07:27:08 AMI bought the SVD-110 Tool Rest and have been using it with the DF 250 to sharpen mower blades and its quick and really precise, no truing and I use the marker method (most blades are coming up between 35° - 40°.
If the blade is uneven, I use the KJ45 with no problem.
I would love to see a video or pics of this. It sounds like a great approach.
Quote from: RichColvin on April 16, 2026, 04:19:10 AMQuote from: Rossy66 on April 15, 2026, 07:27:08 AMI bought the SVD-110 Tool Rest and have been using it with the DF 250 to sharpen mower blades and its quick and really precise, no truing and I use the marker method (most blades are coming up between 35° - 40°.
If the blade is uneven, I use the KJ45 with no problem.
I would love to see a video or pics of this. It sounds like a great approach.
next time I sharpen on I will.