What types of knives Cannot be sharpened?

Author: Rodrick Predovic  |  Last update: Sunday, September 21, 2025

While most cheap serrated knives can be sharpened and made to be as sharp as more expensive serrated knives, micro serrated knives cannot be sharpened. These are recognised by the sharp jagged cutting edge.

What knives cannot be sharpened?

Another giveaway for lower quality steel is micro-serration (tiny teeth along the edge of the blade). Of course, there are exceptions to the rule, but micro-serrations are usually added to make knives feel sharper than they actually are. Those knives can't be resharpened.

Can all knives be sharpened?

ALL knives will benefit from regular maintenance and routine sharpening, whether you do it yourself or bring them to a knowledgeable professional. How often should kitchen knives be sharpened? The frequency of which you need to maintenance and sharpen your knife depends on how often you use it and the knife itself.

Are some knives impossible to sharpen?

Unsuitable steel is the most common reason why knives cannot be sharpened. Such steel is used in so-called cheap knives from no-name knife manufacturers. There are more than 2500 different types of steel with the most varied properties and applications.

What type of knife must not be sharpened using a steel?

We do not recommend using sharpening or honing steels on Japanese knives. That's because Japanese knives are made from very hard steel — alongside the tapered V shape, this harder steel contributes to the effortless feel of Japanese knives.

3 Reasons You Can't Sharpen Your Knives

Is there really a knife that never needs sharpening?

Firstly, let's clarify that there is no such thing as a knife that never needs sharpening. Every knife loses its sharpness over time and with frequent use. However, there are knives designed to last longer without losing their sharpness compared to traditional knives.

Are pull-through sharpeners bad?

Even the adjustable ones are not well suited to all knives. Electric pull through sharpeners remove way too much metal and shorten the life of your knife by years.

Can you ruin a knife by sharpening it too much?

It's crucial not to sharpen your knife too frequently or apply excessive pressure, as this can cause the blade to become thin and brittle.

Why is my knife still dull after sharpening?

Sharpening Angle Too High

In practice, an angle that is only slightly too steep will not dull the edge. Only very high angles will create edges that feel dull. Sharpening at a slightly higher angle will actually speed up sharpening, but at the expense of maximum sharpness.

What is the easiest knife to sharpen?

The Forchner knives are a good example of this. They are softer stainless steel so they are easy to sharpen and they will set you back half of what a knife like a Wustof or Henkel would. The best example of hardened knives would be the Henkel knives with their “ice hardened” blades.

Do knives get too old to sharpen?

The answer is fairly simple. Yes, old knives can be sharpened as long as they are in okay shape.

What dulls a knife the fastest?

Never cut on glass, ceramic or countertops. Those surfaces are harder than a knife's edge and will quickly dull the blade. It's what you cut on that dulls knives, not what you're cutting.

Why can't you sharpen ceramic knives?

Being so hard you can only sharpen and repair them using diamond coated grinding wheels or stones, other standard wheels or stones won't have any effect on them. Diamond coated wheels and stones are much more difficult to use than standard tools, and as you would expect they are very expensive.

What kitchen knives do you not have to sharpen?

First of all, there is no knife that never needs sharpening. But some of them are designed to remain sharp longer than others.

How to sharpen a knife that won't sharpen?

Start with the coarse grit sandpaper and move in one direction along the blade's edge. Repeat the process on the other side of the blade until the edge is sharp enough. Gradually move on to finer grit sandpaper until the knife edge is polished and razor sharp.

What is the best knife sharpener?

How many strokes does it take to sharpen a dull knife?

A dull knife requires a coarse stone and may require more time using the stone. Because it can require many strokes, we suggest that you take up to 10 strokes before alternating sides.

How many swipes does it take to sharpen a knife?

How to use a Manual Knife Sharpener: Place the knife against the coarse side of the sharpener and swipe it across the surface around ten times. This initial step sets the foundation for a sharp edge. Afterwards, switch to the fine side of the sharpener and repeat the swiping motion ten times.

Should I push hard when sharpening a knife?

A lot of people apply far too much pressure when they begin sharpening their knives and this can damage the blades. You do need to apply a certain amount of pressure but this should be really light and only come from your fingers; not your whole hand.

How many times do you pull a knife through a sharpener?

We recommend 6–8 pulls through the sharpener (tip up). If you need that extra degree of sharpness, polish the edge with a few strokes back and forth.

Are whetstones better than a sharpener?

If you work with inexpensive knives or don't mind the cost, by all means, grind away. But there's another reason we prefer whetstones: They are more effective. Even the best electric sharpeners can't get your blades as sharp as a properly-used whetstone.

What do professional knife sharpeners use?

A sharpening stone, also known as a whetstone is a kitchen essential used by professional chefs across the globe.