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5 Reasons Why Some Knives Are Hard To Sharpen & What To Do

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Most knife owners will look into the prospect of sharpening their own knives at some point. When people start sharpening their own knives, they find that some knives are hard to sharpen, and they are unsure how to address this problem. We will examine some of the reasons your knife may be hard to sharpen and the actions you can take to solve your sharpening problem.

There are five main reasons some knives are hard to sharpen.

  1. The knife steel is not of good quality.
  2. The knife steel is hard.
  3. The cutting edge of the knife is an unusual shape or grind.
  4. The knife has a serrated edge.
  5. Your sharpening technique needs practice.

Knife sharpening can be a frustrating undertaking in the beginning until you have a greater understanding of the process and different types of steel. If you are dealing with the frustration of a hard-to-sharpen knife, we may have an explanation for you and what you can do to fix it.

If you are interested in checking out the best whetstones for your knives we recommend and use, you can find them by clicking here (Amazon link).

Why Some Knives Are Hard To Sharpen
Why Some Knives Are Hard To Sharpen

Why Are Some Knives Hard To Sharpen?

There are many different knives available for many different tasks, but one process that you cannot get away from is the periodic sharpening of the knife. When you first unpackage your new knife, it may work well for a time, but the inevitable time will come for a sharpening.

In some cases, try as you might, the knife will simply not sharpen or hold an edge! What is going wrong with the knife sharpening process?

Is it your lack of experience, a problem with the knife itself, or an issue with your sharpener? We will discuss the potential reasons you may have difficulty getting your knife sharp.

1. The Knife Steel Is Poor

Poor steel is one of the most common causes of difficulty sharpening a knife. Many people buy cheap knives, especially for tasks where the knife will be working hard. The thinking is they do not want to damage an expensive knife.

In many cases, opting for a cheap knife means that you get a knife made from a sub-par steel quality, which can be counter-intuitive. It is often better to buy a more expensive, higher-quality steel for hard-working knives.

Poor-quality steel will corrode more easily, making the knife susceptible to rust. Sub-standard steel will not hold an edge very long and will need to be sharpened more frequently. 

Lower-quality steel will be more difficult to sharpen because the fine edge is unstable and rolls over or wears away during the sharpening process, so the knife never becomes sharp.

Poor steel wears faster than high-quality steel, which shortens the life of the knife since each sharpening removes large amounts of steel.

2. The Knife Steel Is Hard

The type of steel used in the manufacture of the knife will significantly contribute to the ease or difficulty of sharpening the knife.

Knives made from hard steel will be difficult to sharpen and will require preferred types of sharpeners to make the task easier. Carbon steel knives hardened to beyond 60 HRC will need quality sharpeners to effectively sharpen the knife. 

Stainless steel is formulated to resist wear, and knife sharpening is essentially trying to wear steel off the edge. This feature of stainless steel that makes it good for knifemaking also makes these knives difficult to sharpen.

TIP: The right tools to sharpen your knives properly can make all the difference to learning the skill and maintaining your knives. Check out the must-have tools to sharpen your knife in the article below:
3 Must-Have Tools To Sharpen Your Knife Properly (Answered)

3. The Knife Blade Has An Unusual Shape

Some knives have unusual blade shapes, which makes the sharpening process difficult, especially if the cutting edge is not straight.

Knives with curved edges, such as a karambit, butcher knives, or some hunting knives with curved cutting edges, can be extremely difficult to sharpen, especially for a beginner to knife sharpening.

Single-bevel knives, such as some Japanese kitchen knives, are difficult to sharpen and require a certain skill level to perfect.

4. The Knife Has A Serrated Edge

Serrated edge knives such as bread knives, some pocket knives, and hunting or bushcraft knives have some or all of the blade serrated.

A serrated edge knife requires different tools to perform the sharpening, such as a diamond rod rather than a whetstone or similar flat surface-style sharpener.

5. Your Sharpening Skills Need Work

One of the main causes for problems sharpening a knife is your sharpening skills are not quite there and still require some practice.

Establishing the correct angle and maintaining this sharpening angle across the entire cutting edge of the knife is one of the most difficult aspects of knife sharpening to master.

Your skills may have developed to the point where you can get a sharp edge on some knives, but others, such as stainless steel knives or single-bevel knives, may be causing you some problems.

TIP: The way to choose a knife sharpening system if you are a beginner is to examine what you want your knife sharpening system to achieve. Check out the best sharpening systems in the article below:
Ultimate Guide: Best Knife Sharpening Systems for Beginners

Why Are Stainless Steel Knives Hard To Sharpen?

Why Are Stainless Steel Knives Hard To Sharpen?
Why Are Stainless Steel Knives Hard To Sharpen?

Stainless steel knives have blades built from a steel alloy that has certain ratios of different steels to give the stainless characteristics.

Stainless steel includes a minimum of 13% Chromium but also incorporates higher levels of manganese, nickel, and molybdenum, imparting additional wear resistance to the steel. 

This higher wear-resistant feature of stainless steel is what makes stainless steel knives hard to sharpen. The process of sharpening a knife abrades or wears steel away from the knife’s cutting edge to create a sharp apex on the edge.

Since stainless steel resists wear due to its composition, it also resists the abrasion of steel from the cutting edge. This stainless steel feature makes it difficult to sharpen and may cause some frustration for beginner knife sharpeners.

Why Are Buck Knives So Hard To Sharpen?

Why Are Buck Knives So Hard To Sharpen?
Why Are Buck Knives So Hard To Sharpen?

Buck knives are a popular brand of outdoor and pocket knives. The company has a long history of producing quality knives for this sector. However, many Buck knife owners have expressed having difficulty sharpening these knives. What could be causing this Buck knife sharpening problem?

Buck knives are made from stainless steel, which we have shown to be difficult steel to sharpen. Many people who have success with sharpening other knives struggle to sharpen Buck knives. This is due to the stainless steel used in the manufacture of these knives. 

Buck has used 440C, 425M, 420HC, and CPM S30V stainless steels in the manufacture of their knives. These stainless steel knives are great for outdoor, hardworking knives, but the steel is notoriously difficult to sharpen.

The only way to establish a good edge on a buck knife is to use a good set of whetstones and a significant dose of patience while sharpening the knife!

TIP: Selecting the right type of sharpener to use on your knives is not as easy as it may seem at first. Check out the complete comparison between electric and manual knife sharpeners in the article below:
Electric Vs. Manual Knife Sharpeners: 5 TIPS How To Choose

What To Do With Knives That Are Difficult To Sharpen?

What To Do With Knives That Are Difficult To Sharpen
What To Do With Knives That Are Difficult To Sharpen

After establishing the reasons why some knives are hard to sharpen, what can you do about the problem?

The solution for a knife that is difficult to sharpen will largely depend on the reason it is difficult to get an edge on the knife.

  • What can you do about a knife made from poor steel? There is no remedy for a knife made from low-quality steel. The best you can do is throw the knife out, buy a new one, and be a little more discerning regarding the steel quality of your new knife.
  • What can you do about sharpening a hard steel knife? Use the right style of sharpener appropriate to the steel type. A good quality sharpener with the appropriate abrasives will make the sharpening task simpler and easier.
  • What can you do to sharpen a knife with an unusual shape? Sharpen the blade in sections, striving to maintain the sharpening angle and the same number of sharpening strokes for each section of the blade. An alternative can be to get your knife sharpened professionally by a knife sharpening service.
  • What can you do to sharpen a serrated knife? The right tools for sharpening a serrated edge is your only option for sharpening a serrated edge. A tapered diamond or ceramic sharpening rod are your best option for getting good results on a serrated edge.
  • What can you do to improve your sharpening skills? As with any newly acquired skill, practice is the only way to improve upon the skills you have learned. Practice your knife sharpening as often as you can, using old knives that you are not too concerned about trashing. Focus on getting your angles correct and consistent across the entire blade’s length.

TIP: Are you looking to buy a new whetstone? Check out our recommendations (we personally use the first three ones):

Our PRO choice whetstones combo (Amazon links):

Our budget choice (Amazon link): Sharp Pebble Extra Large Sharpening Stone Set

Why Are High-Carbon Steel Knives Hard to Sharpen?

High-carbon steel knives are highly prized in the culinary and outdoor world for their ability to maintain a sharp edge for extended periods. However, when it comes time to sharpen them, many find it a bit more challenging than other types of steel. But why is this the case?

One reason why these knives are so hard to sharpen if because the steel is so hard. High-carbon steel knives often have a higher rating on the Rockwell Hardness Scale (HRC). This means the steel is harder, which is beneficial for edge retention but can make the sharpening process more labour-intensive.

The grain structure of the steel used to make these knives also makes them hard to sharpen. High-carbon steel has a tight and uniform grain structure. While this provides strength and edge retention, it also means there’s more resistance when trying to reshape or hone the edge.

High-carbon steel knife blades are very hard, but they are prone to chipping during sharpening. The hardness of high-carbon steel, while beneficial for maintaining an edge, also makes it more brittle. This means there’s a higher risk of chipping the blade during the sharpening process if not done correctly.

High-carbon steel is more prone to oxidation and rust compared to stainless steel. If the blade has started to rust, it can create additional challenges during sharpening.

 The patina that develops on these knives can be desirable in some instances, but when a knife with a patina is sharpened, it can negatively impact the aesthetics of the knife until the patina builds back up. 

Sharpening high-carbon steel knives requires a bit more experience and finesse. The technique becomes crucial to ensure the blade is sharpened effectively without causing damage.

Tip: If unsure, consider seeking guidance from experts or tutorials specifically focused on high-carbon steel knife sharpening.


As you progress with your knife sharpening skills, you will gain knowledge about which knives and types of steel are more difficult to sharpen. You will always find a type of steel or a knife shape that will challenge your skills!

These challenges make you better at sharpening knives and help you learn to determine which type of knives you should buy for your requirements!

TIP: We have compiled a step-by-step process to guide you in getting started sharpening your knives with whetstones. Check this guide out in the article below:
Step-By-Step GUIDE: How To Sharpen A Knife With A Whetstone