Sharpening stones remain our tried-and-true favorite sharpening medium for most hand-tool blades. Theyre easy to use, require only human power, and sell for reasonable prices. But how do you know which stones to choose? We tested a variety of waterstones, ceramic waterstones, and diamond stones—11 sets ranging from 125-grit to 8,000 (more than two dozen stones in all)—to find the best fit for you. We flattened the stones that needed it, then sharpened chisels and plane irons, measuring the time it took for each as well as how much these stones dished out.
Above: To ensure accurate, consistent results, we tested the stones using identical plane irons, always held in honing guides. See our review of several honing guides.
Ceramic Whetstone (Splash and Go “Water”) They are more expensive than soaking stones, but because they do not wear out as quickly as soaking stones, they’re preferred over aluminum oxide soaking stones. Ceramic stones have a much longer lifespan and are ideal for blades with a high Rockwell hardness.
Don’t get in a groove: Flatten your stones
Waterstones and ceramic stones wear by design as the abrasive and binder break down to expose fresh abrasive particles. This keeps the stones working, but also means the stones dish out. So, you need to flatten these stones to prevent your tool edges from mimicking this dished-out shape. (Diamond stones, with their particle-on-metal construction, dont need flattening.)
After sharpening a chisel on all stones, we flattened each stone with a coarse diamond stone.
We used a diamond stone to flatten dished stones, above, but you could also use a dedicated flattening stone.
To measure the dishing that occurs with each stone, we sharpened a 3/4″-wide chisel with a honing guide to equal sharpness on each stone. After cleaning away the swarf, we sprayed each stone with black guide coat—a product used in automotive body work to reveal imperfections when sanding.
The softer Naniwa waterstone (left) dished out the most (black area), while the harder Shapton ceramic stones barely dished out.
Then we made five flattening strokes on each stone, which revealed the extent of the dishing by the coating that remained, as shown above.
Waterstones: Effective and Affordable
▪ Waterstones typically consist of abrasive aluminum-oxide or silicon-carbide particles mixed with a binder that is heated and pressed into a rectangular block. The waterstones we tested cut slower than diamond stones, but about the same as ceramic waterstones.
▪ Waterstones wear quickly, exposing fresh grit to cut the steel. But because theyre softer, they also flatten more easily than other stones. (See examples of fast- and slow-wearing stones lower.)
This King waterstone combines 1,000- and 6,000-grit abrasives in one stone and comes with a handy holder.
▪ Waterstores are the most affordable option. Two-sided stones, above, save even more.
▪ Waterstones must soak for at least 15 minutes before use, a delay not required by other types we tested. Allowing wet stones to freeze or letting fine-grit stones (4,000 and up) soak long-term can cause them to break apart.
▪ Periodically dribble a little water on the stone during use to help it cut better and clear the slurry, known as swarf. These stones tend to be the messiest.
How to choose a sharpening stone, whetstone, ceramic, diamond + Grit Size
FAQ
What does a ceramic stone do?
Do you need to flatten ceramic stones?
Do you use water on a ceramic sharpening stone?
What is the best type of sharpening stone?
Are ceramic sharpening stones accurate?
Ceramic sharpening stones are very accurate when it comes to the grain sizes. Because the ceramic particles are synthetically produced you will know for sure that the 8000 grit sharpening stone actually has a grain size of 8000. In addition, there are many affordable ceramic sharpening stones out there.
Are ceramic stones better than diamonds?
Diamond stones have a metal plate that keeps a surface of small diamonds secure. These stones are hard, so they sharpen blades quickly. However, because diamonds are a precious gemstone, they’re expensive. Ceramic stones are highly durable and effective. However, they’re pricey and hard for the average at-home cook to find on the market.
How to choose a ceramic sharpening stone?
There are many differences in quality between the different ceramic sharpening stones, so always pick the one that will suit you best! Are you looking for a forgiving and calm sharpening stone? If so go with a natural sharpening stone! You might be sharpening longer but the results are amazing! Each sharpening stone has a certain grain size.
What are ceramic sharpening stones?
Ceramic sharpening stones are stones where synthetic ceramic particles are combined and turned into one stone. Examples of ceramic sharpening stones are those produced by Spyderco, Skerper, Naniwa and Shapton. Ceramic sharpening stones are very accurate when it comes to the grain sizes.