Testing the Best Sharpening Stones for Knives and Tools

Bring a fine edge to that set of dull blades with one of these top sharpening stones.

Best Overall

The Norton Waterstone Whetstone Sharpening Starter Kit on a white background.

Norton Waterstone Whetstone Sharpening Starter Kit

Best Bang for the Buck

The Amazon Basics Whetstone Knife Sharpening Stone on a white background.

Amazon Basics Whetstone Knife Sharpening Stone

Best Diamond

The DMT 6-Inch Diamond Whetstones With Bamboo Box on a white background.

DMT 6-Inch Diamond Whetstones With Bamboo Box

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Having a set of dull kitchen knives isn’t just inconvenient; it can also be very dangerous. A good sharpening stone keeps blades razor-sharp, which makes them safer to use. These invaluable workshop and kitchen tools can sharpen the cutting edges of knives, scissors, planes, chisels, and other edged tools.

For those who have a set of dull knives that require a good sharpening, keep in mind that all sharpeners are not created equal. That’s why we opted to test some of the most popular models on the market to suit a variety of blade types and budgets. Read on to learn more about these products and find out why those listed below proved to be among the best sharpening stone options on the market.

  1. BEST OVERALL: Norton Waterstone Whetstone Sharpening Starter Kit
  2. BEST BANG FOR THE BUCK: Amazon Basics Whetstone Knife Sharpening Stone
  3. BEST DIAMOND: DMT 6-Inch Diamond Whetstones With Bamboo Box
  4. BEST KIT: Kerye Premium Knife Sharpening Stone Kit
  5. BEST JAPANESE: Shapton Shaptonstone Traditional Waterstones
  6. BEST CERAMIC: Shapton Kuromaku Ceramic Whetstone Set
  7. BEST NATURAL: Masuta Natural Sharpening Honing Stone
  8. BEST FOR KITCHEN KNIVES: Norton IM313 Multi-Oilstone Sharpening System
  9. BEST FOR POCKET KNIVES: Smith’s Pocket Pal Knife Sharpener
A person using the best sharpening stone option to grind the edge of small blade to maintain a sharp edge.
Photo: Debbie Wolfe for Bob Vila

How We Tested the Best Sharpening Stones

To make the most informed product choices, we started out with 2 days of research. We wanted to learn more about the origins and properties of the natural and synthetic abrasives used for the best sharpening stones as well as the types of whetstones that knife and tool experts recommend for different applications.

Since each choice of whetstone claims highly respected proponents, our selections included aluminum-oxide, silicon-carbide, diamond, ceramic, and natural stone whetstones, both waterstones and oilstones. The different types overlap considerably in what they can do, so the ultimate choice comes down to user preference. Most importantly, we wanted to include a wide range of grits, from about 120 to 12,000, from very coarse stones for renewing damaged blades to very fine stones that polish a blade to a mirror finish, and everything in between.

After vetting more than 50 different products from dozens of manufacturers, we settled on those in this guide. These stones best illustrate the range of high-quality sharpening stones and accessories that may be used to keep an edge on kitchen knives, pocket knives, chisels, and other sharp tools.

We then spent 3 days testing the sharpening stones on dull kitchen knives, pocket knives, and chisels on our own workbench. We started with dull tools and worked through the progression of grits, from coarse to fine, sharpening one large kitchen knife, one small or medium pocket knife, and one chisel with each kit. We used water as the lubricant unless otherwise directed in the manufacturer’s instructions.

During testing, we noted the grit and surface area of the stones and any other features included in the kit, such as a carry case, blade angle guide, or flattening stone. We also recorded the time required to sharpen the tools.

Three sharpness tests determined when sharpening was complete: a light test, a fingernail test, and a paper test. For a quick visual sharpness determination, we examined the blades under a light. Holding the knife straight in front of us with its edge facing upward, we slowly tilted it to the right and left. Parts of the edge that reflected light were dull, but if the edge did not reflect light, it was sharp. Once a blade passed the light test, we gently tapped the edge against a thumbnail. A sharp knife catches on the nail but a dull knife slides without catching. Finally, once a blade passed the fingernail test, we held a sheet of printer paper with one hand and drew the blade down through the paper with the other hand. To pass the paper test, a blade had to glide through the paper cleanly with only minimal force. When a blade passed all three tests, we considered it “sharp” and moved on to the next tool.

The best sharpening stone sets featured quality stones with a large surface area, a progression of grits from coarse to fine or extra fine, and a convenient packaging system for storage. We also considered cost with respect to the durability of the material and expected working life of the stone.

A person using the best sharpening stone option to grind the edge of a chef's knife to maintain a sharp edge.
Photo: Debbie Wolfe for Bob Vila

Our Top Picks

The whetstones described and reviewed here are made of quality materials and will transform a dull edge into a razor-sharp blade without damaging the knife. Our top picks include products from some of the most reputable manufacturers of sharpening stones. Keep reading to learn how they performed in our benchtop sharpening tests and why we count them among the best sharpening stones around.

Best Overall

Norton Waterstone Whetstone Sharpening Starter Kit

Removing dings and getting a severely dulled knife back into top condition takes surprisingly little equipment. The Norton waterstone starter set’s two dual-surface sharpening stones feature four grit levels. It starts with a 220/1,000-grit aluminum-oxide stone that can grind out the imperfections and reprofile a severely dulled blade on the extra-coarse side, then set a nice edge on the medium-grit surface. After a few passes on each side of the 4,000/8,000 stone, that old blade will be sharper than new. Both stones are packed in rigid plastic storage cases that double as nonskid sharpening bases. The kit also includes a 3-inch by 9-inch silicon carbide flattening stone that is used to maintain the sharpening stone surfaces.

We truly appreciated the simplicity of this set. It appears fairly spartan, with just two sharpening stones in their own cases and no carry case to hold the whole kit, but the combined grit selection is ideal for maintaining working blades of all kinds. Some users may want to add a less aggressive grit between 220 and 1,000 for blades that are dull but not damaged, but we found that a few light strokes on 220 worked well even for moderately dull blades.

The Norton waterstones effectively returned our pocket knife, chef’s knife, and woodworking chisel blades to safe and competent sharpness levels. The soft aluminum-oxide material formed a nice slurry for quick sharpening, so it did wear somewhat quickly. The included lapping (aka flattening) stone was a big help. Overall, we deem these to be quality synthetic whetstones in a no-frills package.

Product Specs 

  • Type: Aluminum-oxide waterstones, silicon-carbide flattening stone
  • Grit: 220/1,000; and 4,000/8,000
  • Surface dimensions: 8 inches long by 3 inches wide


  • Starter kit contains 2 combination-grit waterstones and a flattening stone
  • Aluminum-oxide synthetic stones offer a highly consistent sharpening surface
  • Flattening stone maintains a perfectly flat surface on the sharpening stones
  • Each stone comes in its own heavy-duty plastic storage case that doubles as a nonskid sharpening base


  • Each stone is packed individually with no carry case for the whole kit

Get the Norton Waterstone sharpening stone kit at Amazon, Sharpening Supplies, or Best Sharpening Stones.

Best Bang for the Buck

Amazon Basics Whetstone Knife Sharpening Stone

Sometimes all shoppers need is one good sharpening stone. This dual-surface aluminum-oxide waterstone from Amazon Basics is a solid choice for maintaining a sharp working edge. It offers 1,000/6,000-grit surfaces for edge maintenance. The kit includes a bamboo nonskid base and an easy-to-use angle guide.

In testing, the Amazon Basics sharpening stone gave us excellent results on our kitchen knife—which was in a used but semi-sharp condition to begin with. The angle guide helped maintain a consistent edge. However, it was much slower going with our dull pocket knife, which really should have started out on a coarse stone. But with much patience and lots of strokes on the 1,000 grit (medium) followed by a few on the 6,000, we ultimately put a nice edge on that blade as well.

This kit did not come with a storage case, so users may want to keep the small shipping box to keep it in. Blades that are severely dull or damaged will require a coarse grit stone to reset the edge prior to using this stone. A flattening stone (not included) will eventually be needed for surface maintenance when the stone becomes worn with use. This is an affordable option for those just starting out with sharpening. The medium- and fine-grit options are effective and forgiving in that they sharpen slowly and won’t ruin a blade with one or two poorly placed strokes.

Product Specs 

  • Type: Aluminum-oxide waterstone
  • Grit: 1,000/6,000
  • Surface dimensions: 7 inches long by 2⅜ inches wide


  • This kit boasts a very budget-friendly price point for a quality sharpening stone set
  • A dual-grit waterstone, nonskid base, and blade angle guide are included
  • With consistent use, this is an excellent choice for maintaining a sharp edge
  • Blade angle guide reduces the learning curve to help novices develop technique


  • A 1,000/6,000-grit sharpening stone is less efficient for resharpening dull blades
  • Storage case is not included to protect the stone when not in use

Get the Amazon Basics sharpening stone at Amazon.

Best Diamond

DMT 6-Inch Diamond Whetstones With Bamboo Box

Diamond sharpening stones are valued for fast, efficient edge maintenance. They work with water, water-based honing oil, or can be used dry; they are considered essential equipment for sharpening hard materials like ceramic knife blades or cobalt-alloy drill bits. The DMT diamond whetstone kit includes three 6-inch by 2-inch diamond bench stones with coarse, fine, and extra-fine grit surfaces. The set is packed in a convenient bamboo storage case.

The DMT diamond stones did a nice job on all of our blades, but unfortunately they did not come with a nonskid sharpening base. We used a scrap of cabinet shelf liner to secure the stones on the benchtop for sharpening. While we were impressed with the quick results on our kitchen and pocket knives, the fast sharpening pace was especially noticeable on the chisel blade. It only required a few strokes on each stone to true up the back and sharpen the bevel edge—a total time of less than 3 minutes.

The material quality of the diamond surface was excellent. Unlike cheap polycrystalline diamond surfaces we’ve tried out in the past, the monocrystalline surfaces here remained consistent after use. We were initially concerned that the plastic block substrates might flex or allow the diamond mesh to warp, but the surfaces proved to be strong and extremely stable.

Our experience was mostly positive with this kit, but the small surface area was restrictive in a couple of ways. We could not use an efficient sweeping motion to sharpen the large kitchen knife, and the surface was too small to work with our chisel sharpening jig, so we had to carefully freehand it. Still, the price was reasonable for high-quality diamond sharpeners, and the kit delivered fast, effective results.

Product Specs 

  • Type: Micronized monocrystalline diamond bench stones
  • Grit: (extra fine) 9 microns/1,200 mesh; (fine) 25 microns/600 mesh; (coarse) 45 microns/325 mesh
  • Surface dimensions: 6 inches long by 2 inches wide


  • Kit includes lightweight bench stones in 3 different grits
  • Diamond sharpening stones work faster than other stone types
  • This is a low-maintenance system that can be used dry or with water; no stone flattening required
  • Convenient storage case organizes and protects the stones in storage


  • Nonskid stone base or pad needed to hold the stones while sharpening is not included
  • Stones are color coded but not labeled extra fine, fine, and coarse

Get the DMT sharpening stone at Amazon, The Home Depot, or DMT.

Best Kit

Kerye Premium Knife Sharpening Stone Kit

With multiple grit levels and accessories that make the process of blade sharpening more manageable, this kit from Kerye is a worthy tool for sharpening any collection of knives. It features two double-sided whetstones with four grit levels, including 400 and 1,000 for sharpening dull knives and 3,000 and 8,000 for refining cutlery.

The kit comes with a knife guide that helps users hold the right angle for sharpening and a handy leather strop to polish the edge while removing burrs after sharpening. A bamboo holder that serves as an attractive, stable base is included, as is a flattening stone to help keep the whetstones in shape. There is even a pair of cut-resistant gloves for added safety during sharpening.

Our tests found the Kerye sharpening kit to offer the most efficient combination of grits for all-around sharpening needs. We used all four surfaces on each blade and progressed faster than all the competitors in our lineup, except for the diamond stones we tested. The included leather strop finished each blade to a shiny, shaving-sharp edge. After sharpening, it took a little water and a few minutes with the flattening stone to renew the stone surfaces.

Wearing protective gloves while sharpening makes sense, but the pair in this kit was too small for our use—it’s possibly an adult medium, but the size is not indicated. The kit comes in a sturdy cardboard storage case with a magnetic flap closure. It holds everything, looks good, and appears to be fairly durable. This simple kit includes everything necessary to renew or maintain any knife or tool blade.

Product Specs

  • Type: Manufactured waterstone (material not specified)
  • Grit: 400/1,000; 3,000/8,000
  • Surface dimensions: 7 inches long by 2⅜ inch wide


  • There are 2 dual-grit waterstones for truing up neglected blades and fine-tuning sharp edges
  • Kit includes cut-resistant gloves, leather strop, flattening stone, and nonskid base
  • Budget-friendly price makes the all-in-one quality knife and tool sharpening kit even more impressive


  • Kit does not include oil or stropping compound for the included leather strop
  • The included cut-resistant gloves may not fit all hand sizes

Get the Kerye sharpening stone at Amazon.

Best Japanese

Shapton Shaptonstone Traditional Waterstones

Shapton’s traditional Japanese ceramic waterstones hone blades into terrific shape, regardless of the condition in which they start. This hard sharpening stone provides a coarse 120 grit. Each stone offers a large surface area of 8¼ inches long by 2¾ inches wide and comes in a plastic storage box that doubles as a stable sharpening base. User note: Be sure to presoak the stone for 5 minutes before the first use.

The ceramic grit used to make these Shapton sharpening stones is nearly as hard as diamond, so we anticipated that this stone would be aggressive. We soaked it for 5 minutes in cold water and then used medium pressure to remove blade nicks and reset edge bevels. After 12 to 20 strokes per blade, we were ready to move onto a finer grit, sold separately (see the Shapton stone set in our next product entry).

We appreciated this stone’s fast results, larger size, and convenient packaging. The large surface area made it easy to use long strokes with the kitchen knife, and it worked well with our chisel sharpening jig. The heavy-duty plastic box includes holes in the base to let the stone breathe (although it should always be allowed to dry thoroughly before storing), and it elevated the surface to a comfortable height for sharpening our pocket knife. We anticipate the hard binder and grit material will give the stone double the working life of a typical aluminum-oxide stone in a comparable grit.

Product Specs

  • Type: Ceramic waterstone
  • Grit: 120
  • Surface dimensions: 8¼ inches long by 2¾ inches wide


  • Coarse grit can repair chipped edges and reprofile severely dull blades
  • Ceramic whetstone is harder and longer lasting than aluminum-oxide or natural stone
  • Packaged in a durable plastic case that doubles as a nonskid sharpening base


  • A blade angle guide is not included, so proper sharpening technique is required
  • Coarse grit is only suitable for rough sharpening, not fine-tuning the blade

Get the Shapton Shaptonstone sharpening stone at Amazon, Woodcraft, or Hocho Knife.

Best Ceramic

Shapton Kuromaku Ceramic Whetstone Set

Shapton Kuromaku ceramic whetstones quickly bring dull blades back to razor-sharp working condition. After a quick cold-water soak before the first use, these color-coded sharpening stones work with just a splash of water. The hard surfaces work faster and last longer than soft aluminum-oxide stones. This kit includes 320- (blue); 1,000- (orange); and 5,000-grit (pink) whetstones to sharpen and polish dull knives and tools. Each stone is packed in a heavy-duty plastic storage case that doubles as a nonskid sharpening base.

We tested this Amazon-exclusive Shapton Kuromaku bundle as a follow-up to our previous test of the 120-grit (white) stone from the same series. Moving from the blue to the orange to pink stones, with just 8 to 12 strokes on each side of the blade per stone, we saw excellent results in less than 10 minutes. The large surfaces were easy to work with, and the hard material required less downward pressure to work effectively than other sharpening stone types.

These ceramic stones cost nearly twice as much as the more budget-friendly aluminum-oxide stones, but they offer a more comfortable and faster sharpening process due to the larger size and hardness of the surfaces. We liked the color-coded stones and boxes too because they made it easier to find the right stone without opening the box. The stones do not come in a single storage case, but the individual cases nest together for easy storage. Eventually, a flattening stone will be necessary to reshape the surfaces of these stones, which will be an additional cost. In our view, this set would make a good long-term investment with consistently satisfying results.

Product Specs 

  • Type: Ceramic waterstone
  • Grit: 320; 1,000; 5,000
  • Surface dimensions: 8¼ inches long by 2¾ inches wide


  • The 3 ceramic whetstones are color coded to indicate grit: blue (320), orange (1,000), pink (5,000)
  • Each stone is packed in its own plastic storage case that doubles as a nonskid sharpening base
  • Hard ceramic whetstones sharpen faster and outlast natural stone and aluminum oxide
  • Large surface area; easier to sharpen larger blades like chef’s knives and carving knives


  • Individual sharpening stones are not contained in a single carry/storage case
  • More expensive than aluminum-oxide whetstones

Get the Shapton Kuromaku sharpening stone set at Amazon.

Best Natural

Masuta Natural Sharpening Honing Stone

This natural stone from Masuta from an underwater cave off the Japanese coast is renowned for its hardness. As a honing stone, it has an ultrafine grit ideal for fine-tuning and polishing an already sharp edge on knives, razors, and other blades.

At nearly 8 inches long and 2¾ inches wide, there’s plenty of surface area for honing a variety of blades. A nonslip base adds safety, while a handsome leather carrying case protects the stone when not in use. This set also includes a Nagura stone for refreshing the whetstone after each use.

Natural stone may be prized for sentimental reasons, but it is less consistent than manufactured abrasives, so results vary from stone to stone—even within the same quarry. That’s why we approached this test with a bit of caution. Fortunately, our test results were pretty good. Our first look at the working planes of the stone revealed no cracks or texture anomalies, though we did note a few streaky color imperfections. The overall color was more of a grayish-black slate rather than the “ocean blue” as advertised. The surface felt flat, extremely smooth, and consistent to the touch.

Due to the stone’s extra-fine texture, we tested it on knives and a chisel that had already been sharpened with a 5,000-grit aluminum-oxide stone. The Masuta stone was very hard and produced a smooth, shiny finish. Before honing, our blades had already passed our three sharpness tests, so it was difficult to gauge an increase in sharpness. We did note, however, that after honing the chef’s knife, it could easily slice into a tomato skin with the slightest backward draw and no added downward pressure.

We appreciated the aesthetic of natural stone, and while we also liked the natural leather storage case, users should be sure to let the stone dry thoroughly before storing it. We did find the kit a bit overpriced since whetstones a third of the cost produce similar results. Shoppers who are specifically looking for a hard natural sharpening stone with a dense, fine texture that can provide results comparable to a 8,000 to 10,000 grit synthetic should consider this one.

Product Specs

  • Type: Natural waterstone
  • Grit: Extra fine (natural stone does not have a grit rating)
  • Surface dimensions: 7⅞ inches long by 2¾ inches wide


  • A hard, very dense, fine-textured natural stone for honing and polishing
  • Extra-large surface area is convenient for honing larger blades
  • Comes in a quality leather storage pouch with snap closures
  • Set includes a matching Nagura stone for touching up the whetstone’s surface


  • Natural whetstones are more expensive and less uniform than synthetics

Get the Masuta sharpening stone at Amazon.

Best for Kitchen Knives

Norton IM313 Multi-Oilstone Sharpening System

The Norton IM313 multi-oilstone system contains three large sharpening stones on a rotisserie-like axle. The axle rests in a bracket positioned over a honing-oil reservoir to capture any runs, drips, or spills. A dome-shaped cover protects the unit when it’s not in use. With three large sharpening stones always at the ready, this system makes it convenient to touch up kitchen knives quickly and as needed. No need to unpack a kit from storage or soak stones in water ahead of time.

With its 2½-inch by 11½-inch replaceable sharpening stones, this system is ideal for working with larger blades. The kit is offered for general-purpose sharpening with one coarse and one medium silicon-carbide stone and one fine aluminum-oxide stone. Replacements are available for the 100-, 150-, and 320-grit preinstalled stones or in other grit counts for customization. The kit comes with a 16-ounce bottle of food-safe sharpening-stone oil, and the heavy base has a nonskid bottom.

From a purely functional standpoint, we liked the design and convenience of this sharpening system best of all. It’s always ready to use—just open the lid, select the desired stone, and start sharpening. The extra-large sharpening surface area was convenient for making long sweeping strokes across the stone. The silicon-carbide stones were extra hard so that sharpening required very little downward pressure. And even with the seemingly coarse 320-grit “fine” stone, this system easily sharpened edges well enough to pass all of our sharpness tests.

The problem we foresee with this kit is that, at 18 inches long by 6 inches wide by 5 inches high, the unit takes up a lot of space when not in use. It’s not an ideal setup for most small and midsize residential kitchens.

Product Specs 

  • Type: Coarse and medium silicon-carbide oil stones, fine aluminum-oxide oil stone
  • Grit: 100, 150, 320
  • Surface dimensions: 11½ inches long by 2½ inches wide


  • A 3-way oilstone sharpening system for general kitchen sharpening needs
  • Extra-large surface area sharpens large kitchen knife blades faster
  • Replaceable oilstones offer a long working life and slower wear than waterstones
  • A 16-ounce bottle of FDA-approved pharmacopeia-grade mineral oil for sharpening is included


  • Built for commercial kitchens, its large size takes up more storage/counter space
  • Some users may prefer finer grit stones, which are available separately

Get the Norton IM313 sharpening stone system at Amazon, Sharpening Supplies, or Knife Merchant.

Best For Pocket Knives

Smith’s Pocket Pal Knife Sharpener

Pocket-knife blades vary in size and are attached to a large handle, which can make them difficult to sharpen on a standard whetstone. This sharpener from Smith’s features two slots—a carbide one for coarse sharpening and a ceramic one for fine sharpening—making it a cinch to use on smaller blades. And because it has preset angles, this sharpener takes the guesswork out of sharpening while on the go: Simply slide the knife back and forth in each slot to whet it.

One feature we particularly like on the Smith’s sharpener is the retractable, diamond-coated rod that sharpens serrated edges. This compact sharpener fits easily into the pocket of a backpack, allowing users to keep it close at hand while on camping and hunting trips.

The Smith’s sharpener is not a sharpening stone in the truest sense of the word, but it might come in handy when carrying a larger, heavier stone is not possible. We were not able to sharpen a chisel with the two V-notches effectively. But we used the diamond rod and two notches to repair damaged pocket and kitchen knife blades and bring them back to a functional level of sharpness. They ultimately passed our fingernail test, but we could not produce an edge consistent enough to cut paper or to pass the light test.

At just 0.9 ounce, this little sharpener weighed next to nothing and was easy to carry in a backpack or pants pocket. It did not produce the level of sharpness that we needed, but some users may consider using it as an emergency backup. Our preference would be to add a little more weight to the daypack with a stone that will do a more thorough job. We are considering the Work Sharp Guided Field Sharpener for our next round of tests.

Product Specs

  • Type: Diamond-coated rod; carbide and ceramic v-notches
  • Grit: Not given
  • Surface dimensions: Two thin V-notches and a 2-inch diamond rod


  • This pocket-size portable sharpener weighs less than 1 ounce
  • Boasts a wallet-friendly price point for a handy on-the-go maintenance tool
  • Reversible carbide and ceramic notches allow for quick sharpening and extended wear time
  • Diamond rod works with both serrated and standard blades


  • Best for a quick touch-up; not suitable for primary blade maintenance

Get the Smith’s sharpening stone at Amazon, Ace Hardware, or Rural King.

Jump to Our Top Picks 

What to Consider When Choosing a Sharpening Stone

A sharpening stone’s grit level or material type largely determines how well it will sharpen a blade. Read on to learn about grit, materials, and other factors to take into account when shopping for the right product.


Sharpening stones come in different grit levels. The lower the number, the more coarse the stone, while the higher the grit level, the finer. Levels of 120 to 400 grit are good at sharpening exceptionally dull knives or those that have chips or burrs. For standard blade sharpening, a stone between 700 and 2,000 grit works best. A high grit level of 3,000 or more creates an ultrasmooth edge that leaves little to no serration on the blade.


The material used for the sharpener has a lot to do with the edge it leaves on a knife. An oil stone will leave a toothier, sawlike edge on the blade, even with a higher grit level. Waterstones offer higher grit levels for a smoother finish that slices rather than saws. Diamond stones at lower grit levels will leave toothier finishes for cutting soft materials, while a higher grit level will create a finished edge for slicing through harder materials. The material of the sharpener also determines how well the stone will hold up to repeated sharpenings. Softer waterstones need resurfacing periodically, while harder diamond stones do not.


Most sharpening stones are shaped like blocks and are large enough to service most blades. Many have mounting blocks with nonslip bottoms that secure the block to the table or counter and provide a firm base from which to sharpen. Some compact sharpeners have slots into which knives or blades are placed. This design makes sharpening more manageable if slightly less precise because it creates the sharpening angle for the user. Simply slide the knife back and forth in the slot to sharpen the blade. These slotted blocks typically feature a coarse slot for dull edges and a fine slot for finishing.


Sharpeners must have enough surface area to sharpen everything from small knives to large carving knives. Most sharpening stones are around 7 inches long by 3 inches wide by 1 inch thick to allow for enough surface area to sharpen different types of blades.

Types of Sharpening Stones

Sharpening stones are blocks of hard materials, including Japanese ceramic, waterstones, and even diamonds. Coarse sharpening stones restore dull blades, while fine ones hone sharp edges. Most stones have a broad surface area for sharpening and a nonslip base to facilitate the sharpening process. Here are some of the most effective types of sharpening stones available.


Waterstones, as well as some oil stones, are made of aluminum oxide. Waterstones are softer than other types of sharpening stones, which results in faster sharpening. And since they use water to remove the ground bits of metal from the stone, it’s also cleaner than using an oil-based stone. However, since this stone is softer, it will wear out more quickly than other stones, requiring users to restore the stone by flattening it periodically.

Oil Stones

Oil stones are made of novaculite, aluminum oxide, or silicon carbide and use oil to remove small bits of metal for sharpening. This type of stone comes in a variety of grades, from fine to coarse, and is known for creating fine edges on tools and knives because of its hardness. The advantage of oil stones is they are inexpensive and low maintenance. Because they are so hard, they also rarely require flattening. The downside of oil stones is they have a lower cutting rate than the other stone types, which means it takes longer to sharpen a blade than with a water or diamond stone sharpener. Keep in mind that sharpening oil is a requirement to use with oil stones, so there is also extra expense—and mess—involved in using them.

Diamond Stones

Diamond stone sharpeners consist of small diamonds attached to a metal plate. These diamonds are harder than other types of stones (in fact, they are sometimes used to flatten softer sharpening stones) and therefore sharpen blades more quickly. Diamond sharpening stones either have smooth surfaces or small holes for catching the metal filings, and they come in varying degrees of coarseness. Smooth sharpeners are useful for honing the edges of tools and knives with points or teeth that may become caught in the small holes. Diamond stones are the most expensive of the sharpening stones.

Ceramic Stones

Ceramic stones are highly prized for their durability and their ability to create a fine edge on knives. These stones offer exceptional accuracy when it comes to grit levels and rarely need resurfacing. High-quality ceramic stones tend to be more expensive than other stones.

Natural Stones

For thousands of years, natural stone was the primary material used to sharpen blades of all kinds. Many traditionalists prefer natural sharpening stones for the aesthetic appeal and the connection to the past. However, natural stone comes with a few drawbacks, such as inconsistent texture and blemishes within the stone that can make the surface weak. Limited availability of quality material makes natural sharpening stones one of the more expensive options.

Tips for Using a Sharpening Stone

Sharpening stones can restore a set of quality knives, pocket knives, and hunting knives to their former glory. To achieve that, it’s essential to follow a few crucial tips.

  • Assess knives. Determine how dull the knives are and decide what grit to use. Cut test slices through a tomato or another fruit or vegetable. The harder it is to get the knife through the fruit, the duller the knife is. Use a knife that’s already sharp as a benchmark if necessary.
  • Soak the stone. Most stones need to be soaked in water to function correctly. If using a waterstone or ceramic stone, this is a crucial step. If using an oil stone, the stone will need to be prepped with cutting oil.
  • Know the grit. Like sandpaper, sharpening stones have different grit levels. Research which grit level should be used to sharpen a blade properly.
  • Find the 20-degree angle. Most blades should be sharpened at a 20-degree angle, but this angle can be a challenge to figure out. Begin by holding the edge at a 90-degree angle. Tilt it halfway to the countertop to find 45 degrees. Then halve the distance to the surface again to reach roughly 20 degrees.
  • Place the stone on a damp washcloth. If the stone has a nonslip side, users can skip this tip. Otherwise, set the stone on a damp washcloth to hold it in place while sharpening.
  • Test the edge of the sharpened knife on a piece of paper. If users are unsure if they’ve sharpened their knife adequately, they can hold up a piece of paper and attempt to slice down through one edge. If the blade is sharp, it should cut through the paper easily.


If you still want more info on sharpening stone usage and maintenance, read on for answers to the most commonly asked questions about these tools.

Q. How long do you soak a whetstone?

Soak your fine sharpening stone in water for 5 minutes before using it; 10 minutes should be long enough for coarse stones to soak through thoroughly.

Q. How do you use a sharpening stone?

Begin by laying the blade across the stone at a 20- to 25-degree angle. Grasp the knife by the handle with one hand and the dull side of the blade with the other. Pull the blade toward you while making a sweeping motion across the block. Then flip the blade and make the same motion across the block in the other direction. Make 10 strokes on each side, and then test the blade’s sharpness by cutting the edge of a piece of paper. Continue this process until the edge is sharp and slices through paper easily.

Q. How do you clean a sharpening stone?

It depends on the type of sharpening stone. To clean an oil stone, rub a small amount of oil in a circular motion down the stone. For waterstones, use water. This will cause the stone to release the tiny metal particles you’ve sharpened off your blades from its pores. Rinse the stone with water and wipe down with a paper towel. Be sure the stone is fully dry before storage.

Q. How do you flatten a sharpening stone?

Depending on the type of stone, wet the stone with oil or water. For best results, use a flattening stone, also known as a lapping stone. Several of the kits in this guide come with them. In a pinch, sandpaper may be used. Use 100-grit sandpaper to remove any inconsistencies until flat. Then use 400-grit sandpaper to remove any scratches created by the coarse sandpaper. You can also purchase a flattening plate, which is designed for this purpose.

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Meet the Tester

Mark Wolfe is a writer with an extensive background in the green industry and an avid DIYer who lives in a 50-year-old home. When he isn’t writing, he spends his time upgrading, repairing, and replacing anything and everything in his home, yard, and garden. He tests and writes reviews about hand tools, lawn-care and home-repair products, and outdoor-living goods.


Tony Carrick Avatar

Tony Carrick

Contributing Writer

Tony Carrick is a freelance writer who has contributed to BobVila.com since 2020. He writes how-to articles and product reviews in the areas of lawn and garden, home maintenance, home improvement, auto maintenance, housewares, and technology.