KitchenIQ 50009 vs Longzon 4-stage Side-by-Side Comparison

Anh Ngo
Anh Ngo
Reviewer
Nguyen Ntk
Nguyen Ntk
Visual Specialist
Reviewed
Our recommendations are made independently through research and testing following our review procedure. We may receive commissions from purchases made via our links at no additional costs to you.
Tested Using Methodology v1.1
Updated Nov 28, 2022
Tested Using Methodology v1.1
Updated Nov 28, 2022
KitchenIQ 50009 Edge Grip 2-Stage Knife Sharpener Testing and Review
Longzon 4-stage Manual Knife Sharpener Review
Knife Sharpener type
manual
manual
Power
0W
0W

Our Verdict

6.2
Overall Score
  • Performance (50%)
    4.3/10
  • Design (15%)
    8.1/10
  • Ease of Use (35%)
    8.2/10
7.0
Overall Score
  • Performance (50%)
    5.6/10
  • Design (15%)
    9.1/10
  • Ease of Use (35%)
    8.2/10

The Longzon 4-stage sharpener wouldn’t be our first choice for a pull-through sharpener, but it does come out top when compared to the KitchenIQ 50009.

The KitchenIQ’s main selling point is its “edge grip”—a base that can grip onto the edge of your table or kitchen countertop. We’d give a shout out for its solid build and great fitting, too. But where actual sharpening is concerned, it’s among the slowest and least effective handheld sharpeners we’ve tested. 

The Longzon itself wasn’t a top performer when it came to speed and sharpness. But it was much more forgiving of the knife’s edge and its more substantial body was easier to grip and work with. The extra slot for scissors just tops it off as the more practical option.

Performance

4.3
Performance Scores
  • Sharpening Time to Cut a Lemon (35%)
    1.0/10
  • Maximum Sharpness Achieved (20%)
    6.0/10
  • Edge Smoothness (20%)
    6.5/10
  • Material Retention (25%)
    6.0/10
5.6
Performance Scores
  • Sharpening Time to Cut a Lemon (35%)
    1.0/10
  • Maximum Sharpness Achieved (20%)
    6.0/10
  • Edge Smoothness (20%)
    9.0/10
  • Material Retention (25%)
    9.0/10
1.0

Sharpening Time to Cut a Lemon

1.0
  • Sharpening Time: 3 minutes 35 seconds
  • Cutting Feel: Swift and smooth

The KitchenIQ took 215 seconds, or more than 3 minutes to sharpen a knife to the point where it could cut through a big lemon in one single swipe. This may not sound like a terribly long time, but we generally expect faster results from handheld sharpeners. In fact, similar one-stage or two-stage devices take less than half that time to get to the same level. For example, it was 105 seconds for the Sharpal, and 65 seconds for the SunrisePro.

  • Sharpening Time: 3 minutes 10 seconds
  • Cutting Feel: Swift and smooth

The Longzon sharpener was disappointing in this test: It took 190 seconds on average to sharpen a dull knife to the level where it can slice a lemon with ease. Three minutes doesn’t seem so long, but when you’re repeating a motion on a small device, it can feel like an eternity.

Unlike the case with the Mueller, the tungsten carbide blades on this device offer a tight and steady brace. For some reason unknown to us, the knife edge just didn’t get keen quickly enough with it.

6.0

Maximum Sharpness Achieved

6.0
  • Sharpening Time: 6 minutes
  • Sharpness Level: 7 (ripe tomatoes, 1 swipe)

An additional 3 minutes on the KitchenIQ took the test knife from the lemon to the ripe tomato level, and that was its peak sharpness with this device.

Though this is below what most sharpeners can achieve, at this level, the knife’s still capable of most cutting tasks, save for perhaps precision cutting and thin slicing. 

We conducted this test several times over the span of six months and used the device in our kitchen throughout that time. The results were consistent, so at least we can conclude that its abrasives will take a long time to wear down.

  • Sharpening Time: 6 minutes
  • Sharpness Level: 7 (ripe tomatoes)

We doubled the time in the lemon-cutting test and the Longzon sharpener could only up the knife sharpness by one level. It cut through a ripe tomato effortlessly, and took two forceful swipes to sever the tough skin on a chicken breast. This isn’t a bad performance, per se, but we had expected more from the sharpener as it looks so well-made.

6.0

Material Retention

9.0
Kitchen IQ Material Retention
Kitchen IQ 50009 Material Retention
  • Sharpening Time: 1 minute
  • Target Sharpness:

Since its tungsten carbide blades do most of the sharpening, the KitchenIQ peels off more steel from the blade than do most other multi-stage sharpeners. It produces more dust than coarse swarf, suggesting that it acts more like a grinder rather than a serious peeler. This suspicion is confirmed by the relatively fine edges it creates. This was true even when we deliberately applied more force while pulling the knife through. 

Unfortunately, the extra pressure didn’t help much with improving the knife’s sharpness.

Longzon Knife Sharpener Material Retention
Longzon Knife Sharpener Material Retention 1
  • Sharpening Time: 1 minute
  • Target Sharpness:

On most devices that employ tungsten carbide blades as the sharpening ‘abrasive’, the more material they remove, the quicker they work and the sharper the edge. The Longzon is not an exception. It took more than 3 minutes to produce a keen edge, so it’s not a complete surprise that it only removed a moderate amount of material from the edge in 1 minute.

6.5

Edge Smoothness

9.0
Kitchen IQ Edge Smoothness

The KitchenIQ produces an ok edge with no major chips or burrs. The primary edge looks narrow, with visible horizontal grooves and tiny metal grains and fragments. The ceramic rods seem to do their job of refining the edge, making for better results compared to the Smith’s or SunrisePro.

Longzon Knife Sharpener Edge Smoothness

We couldn’t be more impressed when we saw the knife edge after sharpening with the Longzon. It’s smooth, shiny, and balanced between the two sides — common among electric sharpeners, but a rare thing to see with manual pull-through devices. We can’t quite explain the lack of chips, grains, or unfinished shavings — we didn’t need a magnifier to see them on the edge produced by its identical cousin, the Mueller. 

At any rate, if a clean, perfect edge is what you’re after in a handheld sharpener, the Longzon should be among your top choices.

Design

8.1
design Scores
  • Build Quality (75%)
    8.7/10
  • Grip (25%)
    6.5/10
9.1
design Scores
  • Build Quality (75%)
    9.1/10
  • Grip (25%)
    9.0/10

In the Box

KitchenIQ 50009 In the Box
  • The KitchenIQ 50009 edge grip knife sharpener

The device comes in a simple clamshell package. It has four color options. Interestingly, each color is sold at a different price, though they’re all affordable.

Longzon Knife Sharpener In the Box
  • The Longzon 4-stage knife sharpener 
  • Instruction manual
  • Protective gloves 

The Longzon sharpener comes in a nice cardboard box with lots of instructions and contact information printed on it. Then there’s a leaflet that features the instructions in five different languages. Two thin gloves are included in the package, presumably for protecting your hands during sharpening, though this is mentioned nowhere in the manual.

Dimensions

Kitchen IQ 50009 Dimensions
  • Length:
    3.7" (9.4 cm)
  • Width:
    2.0" (5.1 cm)
  • Height:
    1.8" (4.6 cm)
  • Weight:
    2.0 oz (57 g)

Longzon Dimensions
  • Length:
    9.3" (23.6 cm)
  • Width:
    1.8" (4.6 cm)
  • Height:
    3.1" (7.9 cm)
  • Weight:
    8.7 oz (246 g)

8.7

Build Quality

9.1
KitchenIQ 50009 Build Quality

The KitchenIQ deserves a shoutout for its excellent build quality despite its cheap price. The whole sharpener is solid and sturdy. Its parts all fit together seamlessly, leaving no unexpected gaps. We actually dropped it from our countertop a couple times, and it took it well. Even afterward, we didn’t observe any rattling or loose components.

The silicone grip cover was nice to the touch and comfortable to hold throughout the sharpening session.

Longzon Knife Sharpener Build Quality

The Longzon sharpener has a strong build with quality materials and a robust design. Its working section, handle, and base are securely attached to each other, which helps with stability during sharpening. The design is function-oriented, but everything has a nice, flush finish. We couldn’t expect better, especially for its price.

6.5

Grip

9.0
KitchenIQ 50009 Grip
  • Material:
    Silicone

We really like the feel of the grip — it’s soft but offers good friction. It has an ergonomic shape and is connected directly to the base, thus offering great stability.  Its tiny size, however, feels awkward in even smaller hands. Users with large hands will have problems finding a safe place for their fingers.

Longzon Knife Sharpener Grip
  • Material:
    ABS, TPR

The Longzon has a nice, substantial grip. There’s plenty of space for larger hands or for those who want their gripping hand to be as far away from the knife as possible while sharpening.

The upper side of the grip is a plastic that’s very soft to the touch and has decent friction. The lower side features finger nubs for a firmer grip.

Working Section

KitchenIQ 50009 Working Section
  • Levels of Sharpening:
    Coarse, Fine
  • Abrasive:
    Tungsten carbide blades, ceramic rods
  • Mechanism:
    Pull through
  • Sharpening Angle:
    20 degrees

The KitchenIQ offers two levels of sharpening. While the slots themselves are more or less the same size as those on other devices, the whole working section is rather small and doesn’t work well with larger and thicker knives.

Longzon Knife Sharpener Working Section
  • Levels of Sharpening:
    Sharpen, Hone, Polish
  • Abrasive:
    Tungsten carbide blades, diamond rods, ceramic rods
  • Mechanism:
    Pull through
  • Sharpening Angle:
    20 degrees

The working section features one slot for scissors and three for kitchen knives. Instead of a prep slot, you start sharpening your knives with the tungsten blades and use the diamond and ceramic rods for further honing.

The whole working section is covered with stainless steel, making it easy to clean should the need arise.

Base

KitchenIQ 50009 Base
  • Material:
    Silicone
  • Feet Type:
    Edge gripper

Not only is the layout of its working section different from most other devices, the KitchenIQ’s base is special too. It’s a thick silicone pad that covers the grip and extends all the way to the base, creating lots of friction with any flat surface. The cutout in the middle of the base forms an edge grip, allowing you to attach it to the countertop or table edge (as long as that edge is 90 degrees).

Longzon Knife Sharpener Base
Longzon Knife Sharpener Base 1
  • Material:
    ABS
  • Feet Type:
    EVA feet

The Longzon has a red ABS base that makes it look like a Louboutin shoe. It tapers from the working section downwards, but the base size is sufficient to keep the device in place. 

It boasts two flat, but effective, anti-slip pads underneath the working section and the grip.

Ease of Use

8.2
usability Scores
  • Slot Arrangement (10%)
    7.0/10
  • Insertion (20%)
    7.0/10
  • Pulling Through (10%)
    7.0/10
  • Stability on a Clean Surface (40%)
    10/10
  • Stability on a Wet and Dirty Surface (20%)
    7.0/10
8.2
usability Scores
  • Slot Arrangement (20%)
    7.0/10
  • Insertion (20%)
    9.0/10
  • Pulling Through (10%)
    8.0/10
  • Stability on a Clean Surface (40%)
    8.5/10
  • Stability on a Wet and Dirty Surface (10%)
    8.0/10
7.0

Slot Arrangement

7.0
Kitchen IQ Slot Arrangement

The KitchenIQ employs a different slot layout than most others of its type: The coarse slot is placed further from the grip than the fine one. If you’ve used other pull-through sharpeners before, this layout will take some time to get used to. Otherwise, it’s not a problem: The slot names (Coarse and Fine) are printed on both sides of the working section, so pay a little attention and you’ll do it right. This also makes the device south-paw friendly.

Longzon Knife Sharpener  Slot Arrangement

The Longzon’s layout of sharpening slots is identical to the Mueller, and in our experience, not ideal. We’d rather move Slot 3 (diamond rods) to the front of the row to serve as a prep slot.

Otherwise, the arrangement is simple and easy to work with — all the slots have the same grind angle and are designed for the same types of knife edge. The natural progression of coarseness (or fineness) level means you never have to pause halfway through in fear of going the wrong way.

7.0

Insertion

9.0
Kitchen IQ Insertion

You may notice that the tungsten blades in the Coarse slot have distinct corners that protrude from the plastic frame. If you use too much force or are too fast with insertion, your delicate knife edge may end up raking across one of those surfaces and risk chipping or deforming.

Also, the tiny size of the KitchenIQ means the slots are jammed together and are very close to the grip. There’s a real danger of cutting yourself if you’re not mindful while sharpening your knives.

All that being said, insertion was not challenging. We measured the actual openings and found to our surprise that they’re some of the widest among all the devices we tested (6mm).

Longzon Insertion

Insertion was easy with the Longzon: Its wide slots with a neat design offer enough space for the blade to get in without obstruction. You may cut into the wall if you go too fast, but that should be rare.

7.0

Pulling Through

8.0

The KitchenIQ’s sturdy working section and strong base allows for steady operation. Pulling through was effortless, though it’s easy to cut into the plastic frame underneath the sharpening panels if you go too fast.

We noticed that the ‘brace’ is rather loose on this device — the sharpening rods don’t seem to grip to the blade very tightly. This contributes to the rather mediocre sharpening performance.

Longzon Pulling Through

With the U-shaped plastic frame placed too close to the sharpening rods, we ended up cutting into them after almost every swipe. Even a few more millimeters would avoid this. But other than that minor annoyance, the Longzon offers a great sharpening experience. Its blades and rods provide a steady brace with decent and stable friction that’s evident in the near-perfect knife edge it creates. It’s also effortless to keep the blade straight during sharpening — we never ended up with an uneven edge, as was the case with its Mueller counterpart.

10

Stability on a Clean Surface

8.5
Kitchen IQ 50009 Stability on a Clean Surface

With a grip and base made from one solid piece of tough silicone, the KitchenIQ stood perfectly still on a clean countertop as we pulled a knife through it. It has a low center of gravity, so regardless of the force used, the device didn’t wobble one bit.

We tried it on the countertop edge, too, which it’s designed to work on, and were happy with how well it gripped the edge.

Longzon Knife Sharpener Stability on a Clean Surface

Even though the base is tapered, it’s still large enough to support the sharpener. The rubber pads offer good contact areas and great friction, so the device wouldn’t slip on a countertop. We didn’t have to use excessive force to keep it steady during sharpening, just a firm grip.

7.0

Stability on a Wet and Dirty Surface

8.0
Kitchen IQ 50009 Stability on a Wet and Dirty Surface

Like most other devices, the KitchenIQ’s silicone base couldn’t keep it in place on a dirty countertop. To its credit, the device slid but did not shake or wobble like the taller units we tested. Still, given how its grip is so close to the sharpening slots, you run the risk of cutting yourself if things slip. 

The same was observed on a wet and slippery edge: no wobbling, but the silicone foot doesn’t help much in keeping it from gliding along the edge.

Longzon Knife Sharpener Stability on a Wet and Dirty Surface

The slippery countertop wasn’t much of a challenge for the Longzon either. It did glide a bit when we intentionally used more force to sharpen, but it fared well most of the time.