Coreless Steel - Stainless Steel

Coreless steel involves two types of steels with different properties merged together over dozens of layers. The resulting product is a steel that is both highly durable and extremely sharp. Is this steel the right one for you, though? This blog will go further into detail about its processes and composition to help you decide what works best for your needs!

Coreless Steel Stainless Steel - A Damascus Steel that Changed Common Sense

Coreless steel is not only rust-resistant and sharp, but also unique and innovative in terms of its appearance and manufacturing method.

As the name Coreless suggests, this steel material developed by Takefu Special Steel does not use a specific blade steel for the core material, but is made by layering two types of blade steel together - VG10 and VG2.

This approach has two major advantages, which we will go into throughout this blog.


A Special Sharpness Granted by Layering Steels

Normally, blade steels are adopted using a single specification. However, Coreless is a material created by layering VG10 and VG2 together, two blade steels with different hardnesses and wear resistances. Despite us dealing with over 2,000 types of knives and we believe having a great deal of experience in this field, we haven't heard of such blade steel characteristics in any other knives - making this steel truly unique.

Moreover, these knives create fine serrations like a saw blade that are invisible to the naked eye, allowing them to penetrate much more easily into food.

It's said that the due to the way the blade loses its sharpness over time and the naturally forming saw-like serrations that appear from the two layered steel's differences in hardness levels when re-sharpening, that the steel retains an excellent sharpness.


Patterns on the Blade Edge - Unique to Coreless Steel

Damascus steel traditionally featured layering with a soft iron to create beautiful patterns that you seem in many knives today, including our own. Even in high-quality Damascus steel though, these patterns did not extend to the blade edge, which is the actual cutting part. However, Coreless Steel, being layered throughout the blade with different steel types, allows for a beautiful layered pattern that extends all the way to the cutting edge.

This allows for some truly artistic pieces to be made - that also cut amazingly and retain their sharpness.


Steel Mapping Comparison

Steel material is crucial for indicating a knife's initial performance (amongst many other things related to craftsman ability and more). Below are some comparisons to give you some understanding showing what a particular step of the process does in terms of impacting sharpness, balance and maintainability.

Steel Material Heat Treatment/Forging Edge Sharpening Handle Attachment

Sharpness

Balance

Maintainability

There’s three key pointers in the above chart to focus on.

  • Steel Material has a large impact on sharpness and maintainability (ease of sharpening and resistance to rust).

  • Apart from sharpness, heat treatment and the sharpening process in knife creation also have a large impact on sharpness.

  • Measuring a knife’s strengths is more than just its sharpness. Balance and maintainability also need to be considered.

Based on the above steel mapping chart, Coreless Steel falls in this position on the graph below

When comparing various steel types, Coreless occupies a unique position due to its innovative approach. Note that it shares a sharpness very similar to Powdered High-Speed Steel, regarded as an extremely sharp stainless steel.

However, since it's a relatively new material, there is still a lack of both craftsmen that can make these knives, and users that have adopted them. Its true value might become more apparent with extensive, long-term use - and naturally, we can only measure that after more time passes. While its sharpness and sharpening characteristics resemble VG10 (which makes sense, VG10 is one of the layers in Coreless Steel after all), it notably maintains its sharpness over time at a slower rate of decline.

In simpler terms, it can be considered as an evolution of VG10 steel, much like VG10 was an advancement from VG1. However, this is an entirely new steel making method so this feels more like a true evolution, as compared to simply an upgrade.

Cutting power as well as edge retention! Great for long-term use.


Composition Comparison

Let’s look at the tables below and explore the composition of Coreless Steel more deeply. In this instance, we've highlighted both VG2 and VG10 Steels for this comparison to showcase the differences.

Manufacturer Steel Name Carbon Silicon Cobalt Phosphorus Sulfur Manganese

Effect of Material

Hardness

Hardness (⅒ of Carbon)
Oxygen Removal

Decarburization Prevention
Toughness
Wear Resistance

Embrittlement

Embrittlement

Sulfur Removal
Toughness

Listed Value

Average

Maximum

Average

Maximum

Maximum

Average

Aichi Steel

AUS6

0.6

1

0.04

0.03

1

Aichi Steel

AUS8

0.75

1

0.04

0.03

0.5

Aichi Steel

AUS10

1.025

1

0.04

0.03

0.5

Takefu Special Steel

VG1

1

0.5

0.03

0.03

0.5

Masahiro x Daido Steel

MBS-26

0.9

1

0.45

0.04

0.03

0.45

Hitachi Metals

Silver Steel #3

1.025

0.35

0.03

0.02

0.8

Takefu Special Steel

VG5

0.7

0.5

1.4

0.03

0.03

0.5

Takefu Special Steel

VG10

1

0.35

1.55

0.03

0.03

0.4

Takefu Special Steel

VG2

0.65

Undisclosed

Undisclosed

Undisclosed

Undisclosed

Bohler-Uddeholm

AEB-L

0.67

0.4

0.025

0.015

0.6

Manufacturer Steel Name Molybdenum Vanadium Nickel Tungsten Copper Chromium Hardness Rockwell Counter (HRC)

Effect of Material

Wear Resistance
Anti-Corrosion
Toughness

Wear Resistance
Decarburization Prevention

Toughness

Wear Resistance

Antibacterial Effects
Embrittlement

Anti-Corrosion

Changes in the quenching process

Listed Value

Average

Average

Average

Average

Maximum

Average

Aichi Steel

AUS6

0.49

13.75

55.5

Aichi Steel

AUS8

0.2

0.175

0.49

13.75

57.5

Aichi Steel

AUS10

0.205

0.185

0.49

13.75

59.5

Takefu Special Steel

VG1

0.3

0.25

14

60

Masahiro x Daido Steel

MBS-26

0.45

0.1

0.3

0.15

13.75

58.5

Hitachi Metals

Silver Steel #3

13.75

60

Takefu Special Steel

VG5

0.3

0.1

0.25

0.25

14

59

Takefu Special Steel

VG10

0.1

0.3

0.25

0.25

15

60

Takefu Special Steel

VG2

0.15

Undisclosed

0.25

0.25

14

57

Bohler-Uddeholm

AEB-L

13

59

Maker Steel Name Carbon Silicon Cobalt

Effect

Hard.

Hard. (⅒ Carbon)
Oxygen Rem.

Decarb Pvnt.
Tough.
Wear Res.

Listed Value

Average

Max

Average

Aichi Steel

AUS6

0.6

1

Aichi Steel

AUS8

0.75

1

Aichi Steel

AUS10

1.025

1

Takefu Special Steel

VG1

1

0.5

Masahiro x Daido Steel

MBS-26

0.9

1

0.45

Hitachi Metals

Silver Steel #3

1.025

0.35

Takefu Special Steel

VG5

0.7

0.5

1.4

Takefu Special Steel

VG10

1

0.35

1.55

Takefu Special Steel

VG2

0.65

Undisclosed

Bohler-Uddeholm

AEB-L

0.67

0.4

Maker Steel Name Phos. Sulfur Mang.

Effect

Embrittlement

Embrittlement

Sulfur Rmvl.
Resist.

Listed Value

Max

Max

Average

Aichi Steel

AUS6

0.04

0.03

1

Aichi Steel

AUS8

0.04

0.03

0.5

Aichi Steel

AUS10

0.04

0.03

0.5

Takefu Special Steel

VG1

0.03

0.03

0.5

Masahiro x Daido Steel

MBS-26

0.04

0.03

0.45

Hitachi Metals

Silver Steel #3

0.03

0.02

0.8

Takefu Special Steel

VG5

0.03

0.03

0.5

Takefu Special Steel

VG10

0.03

0.03

0.4

Takefu Special Steel

VG2

Undisclosed

Undisclosed

Undisclosed

Bohler-Uddeholm

AEB-L

0.025

0.015

0.6

Maker Steel Name Molyb. Vanad. Nickel

Effect

Wear Res.
Anti-Corrosion
Tough.

Wear Res.
Decarb Pvnt.

Resist.

Listed Value

Average

Average

Average

Aichi Steel

AUS6

0.49

Aichi Steel

AUS8

0.2

0.175

0.49

Aichi Steel

AUS10

0.205

0.185

0.49

Takefu Special Steel

VG1

0.3

0.25

Masahiro x Daido Steel

MBS-26

0.45

0.1

0.3

Hitachi Metals

Silver Steel #3

Takefu Special Steel

VG5

0.3

0.1

0.25

Takefu Special Steel

VG10

1

0.3

0.25

Takefu Special Steel

VG2

0.15

Undisclosed

0.25

Bohler-Uddeholm

AEB-L

Maker Steel Name Tung. Copper Chrom.

Effect

Wear Res.

Antibac.
Embrittlement

Anti-Corrosion

Listed Value

Average

Max

Average

Aichi Steel

AUS6

13.75

Aichi Steel

AUS8

13.75

Aichi Steel

AUS10

13.75

Takefu Special Steel

VG1

14

Masahiro x Daido Steel

MBS-26

0.15

13.75

Hitachi Metals

Silver Steel #3

13.75

Takefu Special Steel

VG5

0.25

14

Takefu Special Steel

VG10

0.25

15

Takefu Special Steel

VG2

0.25

14

Bohler-Uddeholm

AEB-L

13

As you can see, their composition and hardness differs. The Carbon content between the two steels is quite different, with VG10 almost having double the amount, but the rest of VG2 is relatively unknown to the public. Either way, the Hardness ratings are 60 and 57 respectively, so a large difference exists.

The variance in hardness contributes to the continuous formation of fine micro-serrations, providing a sustained sharpness.


Is Coreless Steel Currently the Best Choice?

Firstly, there is a noticable difference between Coreless Steel products on the market currently. While they often look truly beautiful, the amount of craftsmen using this steel that can create knives with proper hardening while removing distortions, and thus bring out the steel's full potential is limited.

When craftsmen push the steel's hardness to it's limit and then perform hammerwork on it, there is a very large risk of the steel cracking. As a result, many Coreless Steel knives on the market may still retain some distortions if you look closely. Before buying Coreless Steel knives - or any knives for that matter, it's very important to inspect it first. Or, talk to professionals like us!


Sharpening will remove the pattern

While this is true for many Damascus knives, it especially strikes true for Coreless Steel Knives. Over time using a whetstone, the pattern on the blade will naturally dissapear or become nearly invisible due to scratches made from the whetstone itself.

Due to the larger lack of nickel in the steels used in Coreless Steel, it can't undergo proper polishing processes, resulting in the blade's wavy patterns becoming more faint and difficult to make shine.

It is possible to maintain the pattern by sharpening only the blade edge of a knife. However, that knife needs special properties such as a high hardness quench, a thin black thickness and is straightened out.

However, since this requires a significant amount of effort in processing, be prepared for prices 2 to 3 times higher than other knives on the market.


Conclusion

Let’s quickly recap the five key points of Coreless Steel here

  • Coreless Steel is a new type of Damascus blade steel that is very unique.
  • By layering two types of blade steel with different hardness levels, it maintains sharpness for a longer duration.
  • It can exhibit patterns all the way to the blade edge, which only this steel can do.
  • Although it is expensive, there can be a noticeable difference in quality among available products.
  • The pattern disappears over time when sharpened.

We don't currently list any Coreless Steel knives on our webstore, however you can always contact us to hear more about our in-store range, or look into custom knife options!