Skip to main content

Carbon-Steel Knives

Published November 2014
Update, November 2018
Some purchasers of our winning carbon steel knife, the Bob Kramer 8" Carbon Steel Chef’s Knife by Zwilling J.A. Henckels, cited discoloration on the blade after use. In most cases, this is completely normal and one of the hallmarks of carbon steel—with use, the metal naturally oxidizes and develops a spotty brown or grey patina. As time goes on, the patina will act as a protective layer against corrosion. That said, it's very important to wash and hand-dry the knife after each use to prevent corrosive rust (which is usually orange in color) from forming. If you do happen to develop a bit of harmful rust on your carbon steel blade, it can usually be removed with a rust eraser. If you're willing to put in a little extra care to your knife, the Bob Kramer by Zwilling remains our top pick for a carbon steel knife—it's a beautifully designed, hardy knife that will last you a lifetime if you treat it right.

How we tested

As serious cooks, we’ve always been intrigued by knives made from carbon steel. This alloy is considered superior to stainless steel by many chefs and knife enthusiasts because it is believed to be harder and stronger and able to take on—and retain—a keener edge. But as practical cooks, we’ve been a bit skeptical. Carbon steel is a high-maintenance metal that rusts if not kept dry, so the makers of carbon-steel knives recommend drying the blade immediately after washing it; some even suggest wiping the blade dry between cutting tasks or occasionally coating it with mineral oil to ward off excessive oxidation, which corrodes the metal. Given that our longtime favorite stainless-steel chef’s knife is virtually maintenance-free, that’s asking a lot.

Still, we wanted to know if carbon steel was truly a cut above stainless. We singled out eight carbon-steel chef’s knives, a mixture of Western- and Japanese-made blades, priced from $72.99 to a staggering $299.95. We recruited seven testers of various abilities to put the knives through our standard cutting tests: mincing parsley, dicing onions, quartering butternut squash, and butchering whole raw chickens. Before and after each round of tests, we sliced through sheets of copy paper; whether the blade cleaved smoothly or dragged indicated how well its edge held up. And all the while, we noted the overall user-friendliness of each model, particularly with regard to the handle.

Battle of the Blades

Some knives had sharp spines or handles that pressed painfully into our palms and caused fatigue. Better grips offered what ergonomists call “affordance”: a shape and texture that allow multiple grips, so hands of all sizes feel comfortable and secure.

As for the meat of our testing—the blade—we homed in on sharpness, which is determined by two factors. First, the thinness of the edge, which is measured by its V-shaped angle. Simply put, the narrower the angle, the cleaner and more precise the cuts. Our top-ranking knives, which were sharpened to between 10 and 15 degrees on either side of the blade, slid through food, while we had to use more force with wider blades that were sharpened to 20 (or more) degrees on either side.

The second determining factor, the strength of the metal, depends on the type of steel that’s used and how it is heat-treated. Manufacturers wouldn’t disclose this information but did share their blades’ Rockwell scale ratings—a measurement of the metal’s strength in a unit called HRC (HR stands for Hardness Rockwell, and strong metals like these are in the “C” class). Sure enough, the highest and lowest Rockwell ratings—60 and above, and as low as 52, respectively—corresponded to the blades’ performances. In fact, our bottom-ranking knife was dull out of the box, with testers comparing it to “cutting with a spoon,” and quickly lost what little edge it had.

To understand why harder blades performed better, we took copies of the knives to Mike Tarkanian at the Massachusetts Institute of Technology’s Department of Materials Science and Engineering. Using a high-powered digital microscope, he zoomed in on the edges of the bottom- and the top-performing blades, which had the lowest and one of the highest HRC ratings, respectively. Immediately we could see why the bottom-ranking knife failed: Even new, its edge looked rounded and dull. Conversely, the top-performing knife’s edge looked as taut as fishing wire, which explained its razor-sharp performance.

Knowing how the carbon-steel knives stacked up against one another, we circled back to our original question: Can carbon steel actually perform better than stainless steel? We decided to pit the best carbon-steel performer up against our favorite stainless-steel knife. We took a brand-new copy of each and tested blade durability by placing a plastic cutting board on a scale (to ensure that each cut would incur the same amount of pressure), making rocking cuts, and repeating the paper cutting test every 10 strokes to track changes. When both blades were still equally sharp after 5,000 cuts, we cut up five more whole raw chickens and butternut squashes with each and then sliced delicate tomatoes. Again, it was nearly impossible to pick a winner. Only after we repeated the scale test on a glass cutting board—hazardous to knife blades—did the knives start to wear down. The carbon-steel model edged out the stainless (which has a Rockwell rating of 56 and a 15-degree edge), but only slightly; both knives still sliced onions with ease.

Their near-identical performance made us strongly suspect that how the metal is manufactured is more important than whether it’s carbon or stainless—a hunch that was confirmed by images of the metals’ grain structures taken at the Boston University Photonics Center. Both looked similarly fine and tight, indicating strong, durable blades.

Given our findings, we can’t justify buying a carbon-steel knife—especially since our favorite stainless-steel model is a bargain and requires no fussy upkeep. But if you are willing to pay a premium and care for carbon steel, our winner is a showstopper. Its razor-sharp blade, sloping ergonomic handle, and good looks make it both visually stunning and a pleasure to use. Our Best Buy is a shade less sharp than our winner, but still impressive.


Seven test kitchen staffers subjected eight chef ’s knives (with blades as close to 8 inches as possible), priced from $72.99 to $299.95, to a battery of kitchen tasks to assess sharpness, comfort, and overall performance. Manufacturers supplied Rockwell ratings (a measurement of the metal’s hardness in a unit called HRC) and blade angles. Scores from each test were averaged to get the overall rating; knives are listed in order of preference. Prices were paid online.

CUTTING: We minced parsley, diced onions, quartered butternut squash, and butchered whole chickens, carrying out each task 70 times per knife. Narrow, razor-sharp blades that cut swiftly and evenly rated highest.

COMFORT: Knives with smooth, nonangular handles of medium width and length rated highest. We also preferred blades with rounded top spines that didn’t dig into our fingers.

EDGE RETENTION: We sliced through paper before and after each round of cutting tests. Blades that kept their original sharpness rated highest.

3 Sites. No Paywalls.

Included in your trial membership

  • 25 years of Cook's Illustrated, Cook's Country, and America's Test Kitchen foolproof recipes
  • NEW! Over 1,500 recipes from our award-winning cookbooks
  • In-depth videos of recipes and cooking techniques
  • SAVE all your Favorites for easy access
  • Up-to-Date reviews and product buying guides

Get America's Test Kitchen All Access — become the Smartest Cook you know, guaranteed.

Email is required
How we use your email address

The Results


Design Trifecta 360 Knife Block

Admittedly expensive, this handsome block certainly seemed to live up to its billing as “the last knife block you ever have to buy.” The heaviest model in our testing, this block was ultrastable, and its durable bamboo exterior was a breeze to clean. Well-placed medium-strength magnets made it easy to attach all our knives, and a rotating base gave us quick access to them. One tiny quibble: The blade of our 12-inch slicing knife stuck out a little.


Schmidt Brothers Downtown Block

This roomy block completely sheathed our entire winning knife set using just one of its two sides—and quite securely, thanks to long, medium-strength magnet bars. Heavy, with a grippy base, this block was very stable. An acrylic guard made this model extra-safe but also made it a little trickier to insert knives and to clean; the wood block itself showed some minor cosmetic scratching during use.


Schmidt Brothers Midtown Block

This smaller version of the Downtown Block secured all our knives nicely, though the blade of the slicing knife stuck out a bit. With a base lined with grippy material, this block was very stable. An acrylic guard afforded extra protection against contact with blades but made it a little harder to insert knives and to clean; the wood itself got a little scratched during use.

Recommended with Reservations

Swissmar Bamboo Magnetic Knife Block

This small, scratch-resistant model had a stable, rubber-lined base and could hold all our knives, though the blade of the 12-inch slicing knife stuck out a bit. But inch-long gaps between its small magnets made coverage uneven and forced us to find the magnetic hot spots in order to secure the knives. Its acrylic guard made it safer to use but harder to insert knives and to clean.

Not Recommended

Messermeister Walnut Magnet Block

This handsome block was done in by its shape—a tippy, top-heavy quarter-circle that wasn’t tall or broad enough to keep the blades of three knives from poking out. It lacked a nonslip base, and its extra-strong magnets made it unnerving to attach or remove our heavy cleaver. Finally, it got a bit scratched after extensive use.


Epicurean Standing Knife Rack 12"

This magnetic block sheathed all our knives completely, though with a bit of crowding. But it was hard to insert each knife without hitting the block’s decorative slats on way down, and because the block was light and narrow, it wobbled when bumped. Worse, we couldn’t take it apart, so splatters that hit the interior were there to stay. Additionally, the outside stained easily, and when we wiped it down, the unit smelled like wet dog.


Kapoosh Rondelle Knife Block

This model stabilized knives with a mass of stiff, spaghetti-like bristles that shed and nicked easily after extensive use, covering our knives with plastic debris. While all our knives fit securely, several of the blades stuck out, making this unit feel less safe overall. Finally, though the bristles could be removed and cleaned in the dishwasher, their nooks and crannies made this block hard to wash by hand.


Kuhn Rikon Vision Knife Block, Clear

This plastic block required us to aim each knife into the folds of an accordion-pleated insert that was removable for easy cleaning but got nicked easily with repeated use. Because we could only insert the knives vertically, longer knife blades stuck out; a cleaver was too wide to fit. The lightest model in our lineup, this block was dangerously top-heavy when loaded with knives.