Samurai Shark Knife Sharpener: What the TV Sharpener Actually Does to Your Edge

Any sharpener that makes a knife cut paper again has sharpened it. That is the common test, and the samurai shark knife sharpener passes it every time. Run a dull blade through the slot and it slices paper again within seconds.

The catch is what that edge looks like up close. A carbide pull through does not grind steel the way a stone or a diamond rod does. It scrapes and tears a rough set of teeth into the edge, and that edge dulls fast.

This guide breaks down what it actually does to a blade, what owners report online, and two sharpeners worth the same money or a little more.

What the samurai shark knife sharpener actually is

It is sold under the Home Smart brand as an As Seen On TV product. The body is ABS plastic, about 6.5 inches long, built around a tungsten carbide sharpening element.

Fixed V slots at the tip handle straight edges, and a retractable component further back is built for serrated knives, scissors, and shears. The maker markets it well past the kitchen, for garden shears, pruning tools, and even mower blades.

Retailers price it anywhere from under 5 dollars on clearance to around 12 dollars in stock at the official storefront. Either way, it sits at the low end of what a sharpener costs.

How a carbide pull through works

A stone or diamond rod grinds a fresh bevel by removing a thin, even layer of steel along the edge. A carbide sharpener works differently. Two hardened carbide points bite into the blade and scrape metal away in a single pass.

People who cut one open describe the result plainly. It scrapes and tears steel rather than grinding it, leaving piles of metal shavings behind. For the fuller picture of how sharpeners in general remove metal, see the mechanics behind different sharpener types.

The samurai shark knife sharpener uses this same carbide scraping method as the V slot sharpeners that came before it. Nothing about the design grinds a true bevel.

What it does to your edge

A toothy edge feels sharp at first because those teeth grab paper and tomato skin easily. That bite fades within a day or two of real use, faster than a properly ground edge would.

The bigger risk shows up if a carbide insert chips. Owners in enthusiast knife communities describe a single chipped point scoring a groove down the entire length of a blade, pass after pass. One owner reported a fillet knife ruined this way.

The serrated knife and scissors claims

Retailer copy calls it the only knife sharpener that sharpens serrated blades. The official listing is more modest, describing a retractable element for serrated knives, scissors, and shears without claiming exclusivity.

Community members who specifically needed a serrated knife sharpened were steered toward tools built around that job instead. That is a signal the retractable slot handles serrations, but not particularly well.

How to use it if you already own one

Third party instructions describe setting the sharpener on a counter edge with the carbide blades facing you. Brace it with your palm at least two inches from the end, then pull the knife through the grooves three to four times.

Neither the retailer nor the instructions specify pressure or a preferred direction. That gap matters, since inconsistent pressure is part of why results vary so much between owners.

Who it is fine for and who should skip it

It is fine for cheap kitchen knives, garden shears, and mower blades where a rough edge is good enough. It also works as a reasonable backup for camping or fishing knives you do not baby.

Skip it entirely on a good chef knife, a fillet knife, or any thin, hard edge you actually care about. A samurai shark knife sharpener has no business anywhere near an actual sword either. See why a sword needs a completely different sharpening approach for that blade geometry.

What owners actually say

The official storefront shows a 5 star average across 24 verified purchases. Enthusiast knife communities tell a different story, with owners near unanimous that it belongs only on disposable kitchen knives.

Recurring phrases include eats your knife, piles of metal shavings, and edges that look like crumbled concrete under magnification. One consistent piece of advice across threads is to keep it for the junk drawer knives and put anything good on a stone or ceramic rods.

A few buyers also reported billing problems when ordering directly through the TV offer, with double charges showing up on their cards. Buying from a retail shelf instead avoids that risk.

Better options for the same money and a bit more

Neither pick below fixes the carbide scraping mechanism itself. Both are simply better built and better reviewed versions of the same idea, aimed at the same beater knife use case.

If a carbide pull through appeals to you but you want more choices first, take a look at how it stacks up against other pull through models. The Bavarian Edge is another As Seen On TV sharpener that runs into similar complaints.

Enthusiasts who want an actual fix skip carbide entirely. They reach for ceramic rods, a guided system, or a basic sharpening stone. None of those are as fast, but all of them grind a true bevel instead of scraping one.

Still weighing which sharpener actually fits your knife block? Answer three quick questions to match a sharpener to your knives before you spend anything.

FAQ

What is it made of?

An ABS plastic body around a tungsten carbide sharpening element, with fixed V slots and a retractable slot for serrated blades and scissors.

Does it really sharpen serrated knives?

The official listing says the retractable element handles serrated knives, scissors, and shears. Owners who needed a serrated edge sharpened well were steered toward dedicated tools instead.

Will it ruin my knife?

On a cheap knife, no. On a good chef knife or fillet knife, the scraping action removes more metal than it should, and a chipped insert can score the blade permanently.

Is the samurai shark knife sharpener still sold?

It was still listed in stock at the official As Seen On TV storefront and at several small retailers as of this writing, though it is unclear whether Home Smart still manufactures it directly.

What should I buy instead?

For the same beater knife job, the AccuSharp 001C and the Sharpal 101N 6-in-1 are better reviewed. For a real edge on knives you care about, reach for a sharpening stone or ceramic rods instead.