VG10 vs D2 Steel

VG10 and D2 are both alloyed steels that have been extensively utilized in the production of high-quality knives.

VG10, developed by the Japanese steel producer Takefu Special Steel, is a chromium-molybdenum-cobalt stainless steel designed for excellent corrosion resistance, hardness, and edge retention.

In contrast, D2 is a high-carbon, high-chromium tool steel known for its exceptional wear resistance, but with slightly less corrosion resistance compared to VG10.

The key differences between these two blade steels lie in their alloying compositions and microstructural characteristics.

VG10’s stainless steel composition, including 15% chromium, gives it superior corrosion resistance over the carbon-rich D2.

However, D2 steel higher carbon content (1.42% vs. 1.0% in VG10) and large volume of carbides result in greater wear resistance and hardness, albeit at the expense of some toughness.

VG10 vs D2 Steel At A Glance 

Hardness

VG10 is designed to have a maximum hardness of HRC 60 according to the manufacturer Takefu Special Steel, in contrast, D2 is typically heat treated to a hardness of HRC 60-62.

The hardness of VG10 knife steel is achieved through its alloying additions of 1.5% cobalt. The vanadium addition also helps refine the microstructure, further enhancing hardness.

In contrast, D2 hardness of HRC 60-62 is due to its higher carbon content of 1.42% leads to a higher volume of carbides in the microstructure.

Toughness

VG10 stainless steel has higher impact toughness than D2 steel.

In a toughness test conducted by Takefu, at 60HRC, VG10 had a toughness similar to SG2 at around 400kgf/mm²  while D2 was reported to have a toughness of around 270kgf/mm². 

VG10 has a finer, more refined microstructure due to its lower carbon content (1.0% vs 1.42% in D2 steel. 

The lower carbon and more homogeneous carbide structure in VG10 allows for greater impact toughness compared to the larger, more numerous carbides found in D2.

The superior toughness of VG10 makes it better suited for uses where the blade may encounter impacts or sudden loads, such as in general kitchen knives or outdoor utility blades.

In contrast, the lower toughness of D2 means it is more susceptible to chipping or fracturing under impact. 

Edge Retention

D2 steel has better wear resistance compared to VG10. In CATRA slicing edge retention tests, D2 was found to have better edge retention than 440C which in turn was slightly better than VG10 stainless steel. 

Better edge retention can be attributed to D2 higher hardness and the large volume of hard chromium carbides in its microstructure, which provide excellent abrasion resistance.

In contrast, VG10 has a hardness of HRC 60 or lower, with a microstructure containing primarily chromium carbides and a smaller amount of vanadium carbides.

While the vanadium carbides improve wear resistance compared to a steel like 440C, the overall carbide content and hardness of VG10 is not quite as high as D2. 

D2 knives will generally maintain their sharp edges for longer periods of time in cutting applications that dull the edge through abrasion, such as slicing, chopping, and industrial applications.

VG10, while still offering good edge retention, would be expected to require more frequent sharpening compared to D2.

This carbide structure, while increasing wear resistance, can also make D2 more brittle and reduce its toughness compared to VG10, this negatively impacts edge stability.

Corrosion Resistance

VG10 is a stainless steel having good corrosion resistance, owing to its 15% chromium content, while D2 steel is a non stainless steel with moderately low corrosion resistance.

In my experience, VG10 performed well in corrosive environments, with no visible signs of corrosion when exposed to distilled water and 1% salt water. 

The 15% chromium in VG10 helps to form a passive chromium oxide layer that protects the steel from corrosion.

In contrast, D2 steel has a higher chromium content at 11.5%, but only about half of that chromium is in solution and available to contribute to corrosion resistance.

The rest is tied up in carbides within the microstructure. As a result, D2 has good corrosion resistance for a tool steel but is not as corrosion resistant as VG10 steel.

VG-10 superior corrosion resistance makes it a better choice for kitchen knives and other applications where the blade may come into contact with wet or corrosive materials.

Ease of sharpening

VG10 is generally easy to sharpen than D2 steel, and easier to sharpen comparable to other stainless steels like 440C and 19C27.

This is due to its lack of significant amounts of carbides in the microstructure, which can make some steels more difficult to grind and sharpen.

D2 is more challenging to machine and sharpen than some other tool steels.

The higher carbon content and large chromium carbides in the D2 microstructure contribute to its relatively poor machinability.

VG-10 knife steel relative ease of sharpening compared to D2 makes it a more user-friendly option for knives intended for home or recreational use.

Final Thoughts on VG10 vs D2 Steel

The key distinguishing factors I’ve noticed between these two steels are their edge retention and corrosion resistance.

D2 is truly a performer when it comes to achieving and maintaining a wickedly sharp edge, almost on par with high-end steels like S30V.

Its combination of high hardness and carbide content makes it an excellent choice for budget-friendly pocket knives that need to withstand heavy cutting.

In contrast, while D2 may have the edge in wear resistance, VG10 shines in terms of corrosion resistance and slightly better toughness. 

Its stainless steel composition, including 15% chromium, provides superior protection against the elements, making it a fantastic choice for both pocket and kitchen knives that will see frequent exposure to moisture.

If you like D2 edge retention but you fear it may corrode easily then get a coated D2 knife, you will get the best of both worlds, edge retention and corrosion resistance.