• Online Events For Landscapers!
    With GIE+EXPO cancelled, virtual education and product launches are filling up the fall. Check out dates for Caterpillar, Exmark, NALP, and more. Click here to learn more.

Best 4" grinding flap wheel to sharpen blades?


LawnSite Silver Member
Long Island
When it comes to grinding steel with a flap disc, I ONLY buy zirconia abrasives. Forget the aluminum oxide crap at HF. If you want to spend a little extra, you can look for a ceramic abrasive.

And yeah, I look for cheap zirconia discs I can find on eBay or Amazon. They're much cheaper in 10 packs.

HF is getting $6.50 to $7 for a single zirconia flap disc
HD is getting at least $8

Here's a 10 pack online for $25

But here's a word of advice. The cheapest discs may not always be the best deal. Look closely at the thickness. That gives an indication of how much wear you may expect to get from them.
These are going for $18 on eBay:

And these are going for $25 on Amazon:

See the difference?