CTS BD1N, manufactured by Carpenter Technology Corporation, is a nitrogen-enhanced version of their CTS BD1 steel, developed to compete with premium stainless steels like S30V from Crucible Industries.
On the other hand, VG10 is produced by Takefu Special Steel in Japan and has been in use since the late 1950s.
CTS BD1N incorporates nitrogen to achieve higher hardness and improved corrosion resistance compared to its predecessor, CTS BD1, while maintaining good toughness.
VG10, in contrast, uses a combination of high carbon content, chromium, molybdenum, vanadium, and cobalt to balance hardness, edge retention, and corrosion resistance.
While both steels offer excellent stainless properties, CTS BD1N generally provides better corrosion resistance due to its nitrogen content.
VG10 is known for its better edge retention and ease of sharpening compared to CTS BD1N.
Notably, CTS BD1N has been popularized by Spyderco in several of their knife models, while VG-10 has been a staple in Japanese cutlery for decades.
CTS BD1N vs VG10 Steel At A Glance
| Properties | VG10 Steel | CTS BD1N Steel |
|---|---|---|
| Manufacturer | Takefu Special Steel (Japan) | Carpenter Technology Corporation |
| Hardness | Typically up to 60 HRC | Capable of 60-63 HRC |
| Toughness | Slightly better (5.8 ft-lbs in unnotched Charpy tests) | Good, but slightly lower than VG10 |
| Edge Retention | Superior, similar to 440C | Good, but lower than VG10 |
| Corrosion Resistance | Excellent | Superior to VG10, similar to Type 410 stainless |
| Ease of Sharpening | Easier to sharpen and grind | Slightly more challenging due to higher hardness |
Hardness
CTS BD1N steel can achieve a higher hardness than VG10 steel when used in knives.
CTS BD1N is capable of reaching a tempered hardness of HRC 60-63, with specific heat treatment data showing it can achieve around 62-63 HRC.
In contrast, VG10 is typically heat treated to a hardness of upto 60 HRC, as demonstrated quoted by Takefu.
The higher potential hardness of CTS BD1N is attributed to its nitrogen content, which increases the amount of nitrogen in solution after austenitizing, leading to higher hardness compared to its non-nitrogen counterpart BD1.
Toughness
VG10 steel has slightly better toughness than CTS BD1N steel, which could be advantageous for knife applications.
Toughness testing data shows that VG10 achieved an average toughness of 5.8 ft-lbs in unnotched Charpy impact tests at a hardness of about 60.7 HRC.
The addition of nitrogen in CTS BD1N, while increasing hardness, may have a slight negative impact on toughness compared to VG10.
In knife applications, higher toughness translates to better resistance to chipping and improved durability, especially under more demanding cutting tasks or when the blade encounters unexpected stresses.
VG10 has a slight edge in terms of overall blade durability and resistance to catastrophic failure during use.
However, it’s important to note that the difference in toughness between Vg10 and BD1N blade steels is relatively small, and both steels are likely to perform well in most knife applications.
Edge Retention
VG10 steel demonstrates better edge retention and wear resistance compared to CTS BD1N steel, which would have a notable impact on knife performance.
VG10 contains a significant amount of carbides, with its microstructure appearing similar to 440C steel, suggesting a carbide volume in the 12-16% range.
These carbides, primarily chromium carbides with some vanadium carbides, contribute significantly to wear resistance and edge retention.
In CATRA slicing edge retention tests, VG10 performed slightly below 440C but still showed good results.
On the other hand, CTS BD1N edge retention is lower than VG10 edge retention and wear resistance.
CTS BD1N is described as a nitrogen-bearing, high-carbon chromium martensitic steel, but its focus is on achieving high hardness and corrosion resistance rather than maximizing wear resistance.
VG10 knife steel superior edge retention would translate to blades that stay sharp longer during use, requiring less frequent sharpening.
Corrosion Resistance
CTS BD1N steel exhibits better corrosion resistance compared to VG10 steel, primarily due to its nitrogen addition.
The nitrogen in CTS BD1N improves corrosion resistance by increasing the amount of chromium in solution.
Nitrogen is less prone to form nitrides with chromium than carbon is to form carbides. This means that more chromium remains in solution in CTS BD1N, which is crucial for corrosion resistance.
CTS BD1N has corrosion resistance similar to Type 410 stainless steel, with the ability to resist corrosion from mild atmospheres, fresh water, steam, and several mild acid environments.
The superior corrosion resistance of CTS BD1N would translate to better performance in humid or marine environments, increased resistance to staining from acidic foods, and potentially longer-lasting appearance with less maintenance required.
Ease of Sharpening
VG10 steel may be easier to sharpen and grind compared to CTS BD1N, which can have a significant impact on knife maintenance.
VG10 has good machinability and is easy to sharpen, due to its microstructure, which consists primarily of chromium carbides.
VG10 is described as being relatively easy to polish, similar to 440C or 19C27 steels, with the only added challenge being occasional large carbides compared to powder metallurgy steels.
In contrast, CTS BD1N is slightly more challenging to work with due to its higher hardness capability (HRC 60-63) compared to VG10 (typically around HRC 60 in the provided tests).
Additionally, the nitrogen content in CTS BD1N, while beneficial for hardness and corrosion resistance, might impede material removal.
Final Thoughts on CTS BD1N vs VG10 Steel
In conclusion, while both VG10 and CTS BD1N are excellent stainless steels for knife making, my personal experience and research leads me to generally recommend VG10.
Having extensively used VG10 in various pocket and kitchen knives, I can attest to its consistent and impressive performance.
My experience with CTS BD1N, though limited to testing rather than daily use, suggests that its main advantage over VG10 lies in its slightly superior corrosion resistance.
However, this difference is negligible in typical everyday use and only becomes apparent in highly corrosive environments.
VG10 steel balanced composition of high carbon, chromium, molybdenum, vanadium, and cobalt results in a steel that excels in edge retention, ease of sharpening, and overall performance.
Moreover, VG10 long history in the industry has allowed manufacturers to perfect its heat treatment process. As a result, VG10 knives often perform better than their specifications might suggest.
While CTS BD1N is undoubtedly a capable steel, particularly in Spyderco’s implementations, VG10’s proven track record and widespread mastery of its heat treatment make it a more reliable choice for most users.
Unless extreme corrosion resistance is a priority, VG10 remains my go-to recommendation between these two stainless steel in knives.