Naniwa Straightening Stone IO-1142 Grit 220

Leveled out my 5+ year old synthetic stone with this in a matter of minutes. Suddenly, my knives keep their edge about 4x longer than before! I'm a professional line cook, so those knives and that stone see a lot of action. I was also able to use the rough backside of this stone to put an edge on a hopelessly dull old pocket knife!

Heavy Duty and Good quality stone. Don't use the cheap Amazon knockoff brands. I learned.

A whetstone won't help if the surface isn't flat. This is perfect for knife enthusiasts who sharpen at home to ensure their whetstones are flat.

Great value. No complaints

i picked up this item to help flatten a badly dished combo stone. it did work, however, this was not the best product for the job. it is so very small and it was broken in half so that made it even smaller. i can't recommend this product for stone flattening in general, but it will do a good job of flattening a particular corner that is high. if you have a very small stone it should be just fine. for standard flattening of normal sized stones i'd say go with a different product.i'd also like to add that after attempting to flatten 1 stone, the half i used had worn down about 50% so it is not a long term stone flattener by any means.

It allowed me to flatten my sharpening stones quickly and accurately.

I wanted to practice flattening my waterstone. So I started using the non-uniform side first. Big mistake. My stone was severely cupped after only 30 seconds or so. So I switched to the other side of this product (completely flat side) and was able to flatten the stone properly. This might work a little better if the stone being flattened has a shorter length than the corrector. My stones are a bit longer than this corrector and it seems like either this or my inexperience is causing a very slight concavity in the final stone. All that being said, this product works very well to get a nice even surface for sharpening!

I have used a full sheet of 120 or 220 grit waterproof silicone carbide sandpaper on a piece of 12”x12” 1/2 inch plexiglass to flatten my water stones for 40+ years. Over all those years I’ve probably spent 50 times the cost of this Naniwa stone on silicone carbide sand paper.The sandpaper method works OK but it’s annoying for a bunch of reasons so I finally broke down and bought this Naniwa flattening stone.The Naniwa is faster than my old method, easier to use and store and the Naniwa leaves a nice finish on all my stones. The Atoma 140 diamond plate is the best tool for flattening but it’s expensive.My only “con” is that I wish it was about 25 % larger. Naniwa makes a bigger flattening stone but it’s about $70. If I need a stone that big, I’ll revert to my full sheet of silicone carbide sand paper and plexiglas.Attached is a photo of the Naniwa stone (black) next to my tan 50 year old King 6000 grit water stone. Hope that helps!