Longzon Knife Sharpener: A Straightforward Look at This Pull-Through Option
If you've come across the Longzon knife sharpener while shopping on Amazon, you're looking at one of the more popular budget pull-through sharpeners on the platform. The honest answer to whether it's worth buying: it depends on what you're sharpening and what you expect from a $20-30 tool.
This guide covers how the Longzon sharpener works, what its four sharpening slots actually do, how it compares to other options at the same price, and when you should spend more or less money on a sharpener.
What the Longzon Knife Sharpener Is
The Longzon is a pull-through multi-slot sharpener typically sold in a configuration that includes four stages: a diamond rod slot for coarse sharpening, a carbide slot for aggressive edge setting, a ceramic slot for fine honing, and a flexible ceramic rod section for scissors.
The housing is plastic with rubber feet for countertop grip. The slots hold your blade at a preset angle, typically 20 degrees per side for Western-style knives, so you don't need to think about angle consistency. You pull the knife through each slot from heel to tip with light downward pressure.
These sharpeners work by removing metal from both sides of the blade simultaneously to create a new V-shaped edge. This is fundamentally different from a whetstone, which lets you control the angle and progression more precisely, but it's faster and requires no skill to use.
How Each Stage Works
Diamond Rod Stage (Coarse)
The diamond-coated rods are the most aggressive stage and are designed for reprofiling very dull knives or repairing minor damage. Diamond abrasive cuts metal quickly, which is both the advantage and the risk. Overusing the coarse stage removes material you can't get back. Use this only when a knife is genuinely dull, not for routine maintenance.
Carbide Stage
Carbide sharpeners use two hardened carbide blades that scrape metal from both sides of the knife edge as you pull through. This is fast and effective for setting an edge on a reasonably dull knife. The same caveat applies: carbide removes metal aggressively. Use sparingly.
Ceramic Stage
The ceramic rods in the fine stage are less aggressive and designed to refine the edge after the coarser stages or for routine touch-ups on a moderately dull knife. This is the stage you'll use most often. A few passes here before cooking can noticeably improve a knife that's lost its bite.
Scissors Stage
The separate flexible ceramic rod for scissors is a nice addition that most pull-through sharpeners skip. It works adequately for basic scissors maintenance, though professional-grade scissors benefit from proper resharpening rather than a pull-through slot.
What the Longzon Does Well
For under $30, the Longzon delivers on a few things consistently:
Convenience. No learning curve, no setup, no water stones to flatten. Pull the knife through, done. For someone who hasn't sharpened their kitchen knives in years and just wants them to work again, this gets the job done.
Consistent angle. The fixed-angle slots remove the most common mistake in whetstone sharpening, which is inconsistent bevel angle. Everyone who uses the Longzon gets the same 20-degree edge.
Scissors sharpening. Most kitchen households have at least a few dull scissors. The ceramic rod slot handles this passably.
Speed. Sharpening a knife with a whetstone takes 5-15 minutes per knife for a beginner. The Longzon takes about 60 seconds.
What the Longzon Doesn't Do Well
Pull-through sharpeners in this price range have real limitations worth understanding before you buy.
Steel removal rate. The carbide stage removes metal quickly and somewhat crudely. With frequent use, you'll shorten the lifespan of your knives faster than whetstones would. If you're using this weekly on a $150 knife, you'll notice the blade getting noticeably shorter within a few years.
Edge quality. The edge from a pull-through sharpener is functional but not refined. Under magnification, pull-through edges show a wire burr that a final strop or fine whetstone pass would remove. For everyday cooking this rarely matters, but if you want the cleanest possible edge for delicate work, a pull-through isn't the path to it.
Japanese knives. The fixed 20-degree angle is wrong for Japanese knives sharpened at 15 degrees per side. Using a 20-degree pull-through on a 15-degree Japanese knife technically sharpens it but changes the blade geometry and dulls the knife's character. Don't use the Longzon on Shun, MAC, Global, or similar Japanese knives.
Very thin knives. Thin blades can flex slightly in the slot, creating an inconsistent edge. This is more of a problem with flexible fillet knives than stiff chef knives.
If you're shopping for a complete knife kit upgrade, our Best Knife Set guide can help you evaluate both knives and maintenance tools together, and our Best Rated Knife Sets guide is worth a look if you're building from scratch.
Longzon vs. Other Pull-Through Sharpeners at the Same Price
At the $20-40 price point, the Longzon competes with KitchenIQ, Presto EverSharp, and similar multi-slot options.
vs. KitchenIQ Edge Grip
The KitchenIQ uses carbide and ceramic stages only, without the diamond rod. This makes it slightly less aggressive and appropriate for regular maintenance rather than heavy-duty reprofiling. For keeping already-decent knives sharp, the KitchenIQ is arguably a better tool because the diamond stage on the Longzon encourages overuse.
vs. Presto EverSharp
The Presto is electric rather than pull-through, which gives more consistent pressure across the blade. It runs about $40-50 and performs more evenly than any manual pull-through in this range. If you want the best budget electric sharpener, Presto is a better recommendation than any manual pull-through including the Longzon.
vs. Spyderco Sharpmaker
The Sharpmaker is a ceramic rod system at around $70 that requires more technique than a pull-through but produces a better edge. For someone willing to spend 15 minutes learning the basic technique, the Sharpmaker is a significant upgrade in edge quality.
When the Longzon Makes Sense
It makes sense if you're in one of these situations:
- Your knives are all Western-style and were bought at a department store for under $100
- You want something easy enough that everyone in the household can sharpen a knife before they cook
- You're a renter or frequent mover and can't set up a proper sharpening station
- You want a cheap scissors sharpener as much as a knife sharpener
It doesn't make sense if you've invested in Japanese knives over $100 each, if you care about maximizing knife lifespan, or if you want to develop actual sharpening skills.
FAQ
How often should you sharpen knives with the Longzon?
For regular home cooks, the ceramic stage once every 2-4 weeks for maintenance and the carbide or diamond stages only when the ceramic stage stops making improvement. Avoid running knives through the coarse stages more than a few times per year.
Can you use the Longzon on serrated knives?
No. Serrated knives have individual serrations that require a tapered rod sharpener to touch up, not a flat pull-through slot. You can run a serrated blade through a pull-through stage without causing harm, but you won't meaningfully sharpen the serrations.
Will the Longzon work on ceramic knives?
No. Ceramic blades require diamond-coated sharpeners specifically designed for ceramic at very fine grit. The Longzon's carbide stage will not sharpen a ceramic blade.
Is the Longzon better than a honing steel?
They do different things. A honing steel (or ceramic rod) realigns the edge without removing material. The Longzon removes material to create a new edge. For regular maintenance between full sharpenings, a honing rod is less damaging. For a knife that's genuinely dull, the Longzon will fix it faster than a honing rod.
The Bottom Line
The Longzon knife sharpener is exactly what it appears to be: a capable, inexpensive pull-through sharpener that makes knife maintenance accessible to anyone. It will sharpen your Western kitchen knives, handle your scissors, and not require any skill to use effectively.
The limitations are real. It's not for Japanese knives, it removes more steel than necessary if overused, and the edge quality falls short of what a whetstone produces. But for a household with standard Western knives that haven't been sharpened in a year, the Longzon gets them back in cooking shape quickly and affordably.