Work Sharp Ken Onion Review: Effective, Versatile, Loud & Cumbersome

By Anh Ngo | Updated
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We were excited when the Work Sharp Ken Onion arrived at our test kitchen. We bought it for $129, so it was cheaper than the Chef’s Choice Trizor XV, but it looks so much more complicated and ferocious. 

We even used it to fix some of the test knives that manual sharpeners couldn’t handle. We’ve run more than a dozen knives through it so far.

The Work Sharp Ken Onion offers many options in terms of both edge angle and sharpening speed. Plus, it creates edges with mirror-like sheens to them. The device is not particularly difficult to use either, though it takes a while to get the hang of it. Setup was the only part that caused us a little frustration. 

Work Sharp Ken Onion Review
(By Nguyen Ntk/HealthyKitchen101)

We recommend this to cooks who appreciate the beauty of a razor-sharp edge and don’t mind spending some effort to get there.

Work Sharp Ken Onion WSKTS-KO-W: The Specs

  • Item weight: 3.1 pounds
  • Dimensions: ‎5.5 x 10 x 6 inches
  • Type: Electric  
  • Wattage: 150W
  • Sharpening Mechanism: Pull-through 
  • Sharpening angle: 15 to 30 degrees with 1-degree increments
  • Bevel type: Single bevel, dual bevel
  • Levels of Sharpening: Extra Coarse (P120), Coarse (X65), Medium (X22), Fine (X4), Extra Fine (6000)
  • Warranty: 3 years

Unboxing the Work Sharp Ken Onion

The Ken Onion comes with a sharpener, a bag of five abrasive belts, a quick-start guide and a detailed (read: long) user’s manual. 

Unlike the sleek Chef’s Choice Trizor XV, the Ken Onion has a robust, brawny body with lots of visible screws, levers, and complicated parts. There are a plethora of nooks and crannies on its body — we suspect some are there solely for aesthetics. The appearance can be a bit intimidating unless you’re handy with electric tools. It really looks like a power tool that belongs in the garage. 

The outer shell seems to be made of rather mediocre, unpolished plastic, which probably explains the affordable price. 

The Work Sharp Ken Onion has a brawny look
The Work Sharp Ken Onion has a brawny look (By Nguyen Ntk/HealthyKitchen101)

Each of the five abrasive belts are color-coded. The names and grits of the three you’ll use most (Coarse, Medium, and Fine) are also printed on the inside of the belt. The Extra Coarse and Extra Fine belts, meanwhile, are easily distinguishable by their texture. All the names, grits, and uses are also in the manual, so you have plenty of references.

The user manual is long but easy to follow. We particularly appreciate the reference chart for sharpening different types of knives. Each is listed with the angle, speed, necessary belts, and number of strokes per side. That was a great resource for first-timers like us. 

Versatility: Covers Your Whole Blade Collection

Most serious cooks amass mixed collections of knives to serve different cutting needs: single-bevel knives for filleting, dual-bevel for casual tasks, small edge angles for thin slicing, large angles for chopping, serrated knives for bread, etc. If you have a bunch of blade types, the good news is the Ken Onion can sharpen almost every single one of them.

The unit sports a sharpening-angle guide that can adjust between 15 and 30 degrees at 1-degree increments. That’s more angle options than any other device we know of. Its own predecessor, the Work Sharp Standard, is capable of only 20 or 25 degrees. And despite its notoriety, the famous Chef’s Choice Trizor XV gives you only a single 15-degree angle.

The user manual recommends progressing from the Coarse (X65) to Fine (X4) belts for sharpening, honing, and polishing kitchen knives. Those were enough to recreate the edges on the test knives used during our experiments with manual sharpeners. 

The Extra Coarse belt should generally be reserved for larger and thicker tools, but it does a great job of fixing visible chips and dents on your kitchen knives if need be. Just be cautious: set it to a low speed, alternate between the sides constantly, and don’t go overboard with the swipes. 

Work Sharp Ken Onion Abrasive Belts
By Nguyen Ntk/HealthyKitchen101

Sharpening angle and coarseness aren’t the only things you can adjust. You also have full control over the belt’s speed. A small knob on the power switch allows you to adjust the speed between 1200 and 2800 SFM (surface feet per minute). There’s no speed indicator, however, so you have to just estimate.

Work Sharp Ken Onion Speed Control
You’ll have to go by range when it comes to speed control (By Nguyen Ntk/HealthyKitchen101)

Sharpness: A Razor-sharp Edge

Out of all the devices we tested, the Work Sharp gave us the sharpest edges and best performance. 

Our test knife went from uselessly dull to being able to cut through raw beef tendon in one single draw after 8.5 minutes of sharpening. That’s sharper than when it was brand new! The only other way to get to that point is to use a set of three or more stones. That would take at least twice as long and would demand skills most of us don’t have.

Sharpening Times As Tested

Level1. Tofu2. Scallion3. Celery4. Carrot5. Apple6. Lemon7. Ripe tomato8. Raw chicken breast with skin9. Raw beef tendon
20° knife8 secs18 secs30 secs39 secs2 mins 4 mins 38 secs5 mins 0 secs5 mins 40 secs8 mins 29 secs

* Knife sharpened from can’t-cut-paper dullness

For most kitchen cutting tasks, 4.5 minutes would be more than sufficient. That was the time it took to sharpen a 20-degree knife to Level 6+ (able to cut through a whole lemon in one clean draw) from complete dullness. 

If you maintain your knives regularly, 30 seconds (a few swipes) will be enough to give it a nice keen edge.

The Work Sharp took a minute or two longer than the Chef’s Choice Trizor XV to achieve the same sharpness in our tests. However, unlike the Trizor, it can sharpen to the knife’s original edge angle, thus preserving the edge as designed. You won’t have to make difficult compromises between sharpness and edge retention.

You can go even further with the Extra Fine micromesh belt, but the Fine aluminum oxide belt is enough to polish the edge to a smooth, mirror-like finish. Your kitchen knives will glide through food without tearing the surface or squishing the innards. Again, the only other way to reach this point is to spend hours using numerous specialized stones. 

We noticed reports of the belts being too small and wearing out quickly, but so far we haven’t had that problem. We’ve sharpened and re-edged more than a dozen knives with them. And now, even at low speed, the Coarse and Medium belts will quickly raise a burr along the edge.

Noise: Not for the Faint-Hearted

The Work Sharp’s biggest drawback is noise. Measured with an Apple watch, the Coarse belt produced 88 dB. That’s roughly as loud as a hairdryer, and is enough to make the Ken Onion the loudest among all the electric sharpeners we tested. 

The Ken Onion on its loudest mode is as noisy as a hairdryer
The Ken Onion on its loudest mode is as noisy as a hairdryer (By Nguyen Ntk/HealthyKitchen101)

If you sharpen tools with the Extra Coarse belt on high speeds, expect it to reach the low 90s. Prolonged exposure to noises this loud can cause health problems, so ear protection is a good idea. Use this setting only as instructed in the manual and avoid binge-sharpening your knives using the Extra Coarse belt. 

Safety: Wear Your Mask

The Work Sharp Ken Onion can stay on the table or countertop while you sharpen your kitchen knives. It’s heavy and solid, so it’s not going to slip or tip over.

If you use it for grinding, though, you will have to pick it up and attack the blade manually, so there’s more risk that way. This risk is minimal, however, because the device’s handle is ergonomic and tacky enough for a good grip. 

Because the abrasive belt is exposed at all times, the unit is not as safe as the Trizor XV, whose wheels are covered by the blade guides. At its size and design, the Ken Onion is not likely to cause serious injuries, but it’s still best to keep children and pets away while you sharpen your knives. It’s also a good idea to release the power switch and turn the device off as soon as you finish sharpening.

Work Sharp claims the device can work for one hour straight and our testing confirmed this.

Work Sharp Ken Onion Safety
By Nguyen Ntk/HealthyKitchen101

We checked the device’s temperature after that test hour. It measured 39°C or 102.2°F — warm to the touch but not nearly enough to cause burns. 

As expected, the coarser belts do remove a noticeable amount of material, turning it into metal dust that gets propelled into the air. We found quite a lot of it on the table after sharpening. It also accumulated quickly in all the corners, slits, and spaces on the sharpener’s body. 

If you’re working closely with the sharpener, that dust is likely to get into your eyes and airway. It’s a good idea to wear a protective mask and eyewear while you’re sharpening.

Ease of Use: Designed for Blade Enthusiasts

The Work Sharp Ken Onion offers more flexibility than any other electric sharpener out there, but that means it’s also more complex. 

Unlike the disc systems in the Chef’s Choice or Presto, the Ken Onion’s design isn’t very intuitive. It took us a while to figure out how to set it up. Adjusting the angle, installing the belt, setting the edge guide, setting the speed, turning it on, and locking the power switch all took a little learning. 

If you have small hands you might find it tricky to press the lock button and hold the power switch at the same time. We initially resorted to holding the handle in one hand and pressing the button with the other. We had to go through three or four knives before the whole setup began to feel natural.

Work Sharp Ken Onion with Small HandsWork Sharp Ken Onion with Small Hands
For those with small hands, speed control and locking while holding the device can prove challenging (By Nguyen Ntk/HealthyKitchen101)

The sharpening process itself wasn’t all smooth sailing. Unless you’re only polishing your knives, a full sharpening run means progressing through the belts. Because they fit rather tightly, they can be frustrating to remove and install.

Although there is a guide on each side to keep the blade stable and the sharpening angle consistent, our first few attempts came out with uneven bevels. A quick search on Amazon revealed we weren’t the only users with this problem.

It took us a couple of knives to learn the machine’s quirks. Here are a few tips for the rookies:

  • Look directly down on the machine from above to make sure your knife’s spine is aligned with the guide as you steadily pull the blade through.
  • Apply just a little pressure against the angle guide to keep the angle stable at all times. (The user manual advises against this, but this was the only way we could get even bevels.) 

All that being said, the Work Sharp isn’t overly challenging to use. It’s a piece of cake compared to sharpening stones. It’s more difficult to go wrong with guided angles, and the motor makes things so much faster. Plus, you need no oil or water, so it’s a lot less messy.

Once you’ve gotten familiar with the system, sharpening can be simple and even enjoyable.

Storage and Maintenance: Simple

Given its complex exterior, you’ll need to use a dry, soft brush every now and then to clean it off. 

The abrasive belts are the only accessories, so this unit doesn’t have a huge footprint (that is, unless you buy all the extra attachments). However, it shouldn’t stay on a countertop to collect dust, oil, or water. A deep drawer or cupboard is the best place to keep your Ken Onion. It may help to cover the device with a cloth to ward off dust.

The Verdict: Should You Buy the Work Sharp Ken Onion?

The Work Sharp Ken Onion is a very versatile tool that accommodates most types of kitchen and outdoor knives. It creates keen edges comparable to what’s achieved with a series of whetstones but makes it easier to maintain the right bevel angle. Usage can be a little tricky and may take some time to get used to. It’s up to you to decide if the high grade of sharpness is worth that extra time and effort.

Buy It If

  • You have a lot of blades to work on
  • Your knives come in different sizes, bevel types, and edge angles
  • You have blades other than kitchen knives to maintain
  • Mirror-like edges bring you great joy 
  • You don’t mind putting some effort but don’t want to spend hours using whetstones
  • Geeky tools interest you 

Not Your Best Choice If

  • You like it quick and simple 
  • You’re only looking for casual maintenance
  • Complicated tools frustrate you
Anh Ngo

Anh Ngo has been writing and editing at Healthy Kitchen 101 since 2018. She tests and reviews a wide variety of kitchen tools and appliances, including knives, knife sharpeners, water filters, and juicing machines. Her feline assistant, meanwhile, is responsible for product box and packaging inspections at the lab.

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