VG10 and S35VN are two distinct stainless steel grades widely used in the production of high-quality knives.

VG10, introduced by Takefu Special Steel over 60 years ago, is a conventionally produced martensitic stainless steel that incorporates chromium, molybdenum, vanadium, and a unique cobalt addition to enhance tempering resistance. 

On the other hand, S35VN, developed by Crucible Industries in 2009, is a powder metallurgy steel designed to offer superior toughness and machinability compared to its predecessor, S30V, by substituting some vanadium with niobium to form a combination of hard vanadium and niobium carbides.

VG10 can achieve a maximum hardness of upto 60 HRC, while S35VN can reach up to 64 HRC with proper heat treatment.

S35VN achieves its higher hardness through a combination of vanadium and niobium carbides, which are harder and more effective at providing wear resistance than the chromium carbides in VG10. 

In contrast, VG10 relies primarily on its chromium carbide content and a cobalt addition to improve tempering resistance.

Higher hardness in knives generally translates to better edge retention and wear resistance, but can also make the steel more prone to chipping or breaking if the toughness is not optimized.

S35VN steel has superior toughness compared to VG10 steel. 

In the unnotched Charpy impact tests, S35VN achieved an average toughness of 6.5 ft-lbs at 60.7 HRC, while VG10 had a lower toughness of 5.8 ft-lbs at a similar hardness.

In the Transverse Charpy C-notch Testing carried out by crucible, S35VN steel achieved an impact energy of 12.0ft-lbs while VG10 steel is expected to attain around 10.0ft-lbs.

S35VN’s higher toughness can be attributed to its powder metallurgy production process and optimized composition.

The powder metallurgy route enables a homogeneous and fine distribution of carbides, leading to a more uniform microstructure with fewer stress concentration points that can initiate fractures.

Additionally, S35VN alloy composition, combining vanadium and niobium carbides, contributes to its enhanced toughness compared to VG10, which primarily relies on chromium carbides.

The niobium carbides in S35VN make it 15-20% tougher than its predecessor, S30V, without compromising wear resistance.

Furthermore, the powder metallurgy process used for S35VN results in superior dimensional stability and grindability, improving its overall toughness and performance in knife applications.

CPM S35VN knife steel offers better edge retention and wear resistance compared to VG10 knife steel.

S35VN steel advantage in wear resistance and edge retention can be attributed to its optimized chemistry and powder metallurgy production process. 

The presence of hard vanadium and niobium carbides in S35VN contributes significantly to its wear resistance.

These carbides are harder and more effective at providing wear resistance than the chromium carbides present in VG10.

Additionally, the powder metallurgy process used in producing S35VN results in a fine, uniform distribution of these hard carbides, maximizing their wear-resistant properties.

Experimental data from CATRA (Cutlery & Allied Trades Research Association) testing supports S35VN  better edge retention, with S35VN estimated to be around 145% of the edge retention of 440C stainless steel, while VG10 is reported to be slightly below 440C.

The finer and more uniform carbide distribution in S35VN, achieved through the powder metallurgy process, also contributes to its improved edge retention by minimizing the potential for carbide pull-out or fracture during use.

In knives, superior wear resistance and edge retention translate to blades that can maintain their sharpness for longer periods, reducing the need for frequent sharpening. 

VG-10 and S35VN exhibit comparable levels of corrosion resistance, with no significant difference between the two steels.

VG10 and S35VN have comparable corrosion resistance ratings, with VG10 scoring 7 out of 10 and S35VN scoring 7 out of 10 on a general 10-point corrosion resistance rating scale.

The similarities in corrosion resistance can be attributed to the comparable chromium and molybdenum contents in the two steels, as these elements play a crucial role in promoting passivation and inhibiting corrosion.

Additionally, the powder metallurgy process used in producing S35VN knife steel does not appear to significantly influence its corrosion resistance compared to the conventionally produced VG10.

VG10 being a conventionally produced steel without significant amounts of vanadium carbides, is generally considered easier to sharpen and grind compared to S35VN.

The absence of hard vanadium carbides in VG-10 allows for more efficient material removal during sharpening and grinding processes.

Most sharpening abrasives are typically made of aluminum oxide which are harder than the chromium carbides present in VG10.

On the other hand, S35VN, being a powder metallurgy steel, contains a combination of vanadium and niobium carbides, which are harder than the commonly used abrasives.

This can make sharpening and grinding S35VN more challenging, as the hard carbides tend to dull the abrasives more quickly, requiring more frequent dressing or replacement.

However, the fine and uniform distribution of carbides in S35VN, achieved through the powder metallurgy process, can somewhat mitigate this issue.

For knives, ease of sharpening and grinding is an important consideration, as it affects the maintenance and longevity of the blade’s edge.

VG10 knives may require less effort and time during sharpening sessions, potentially reducing the risk of overheating or damaging the blade.

However, S35VN superior wear resistance and edge retention could offset the need for frequent sharpening, balancing maintenance requirements and cutting performance.

In my opinion, S35VN steel has the best overall balance of properties compared to the other two steels.  

S35VN stainless steel toughness, wear resistance, and edge retention make it an outstanding performer in demanding knife applications.

However, VG10 should not be overlooked, as it does not fall far behind in terms of overall performance.

VG10 comparable corrosion resistance, decent hardness, and ease of sharpening and grinding, combined with its significantly more affordable cost, make it an attractive option.

If exceptional wear resistance, edge retention, and toughness are what you are looking for, S35VN steel is the clear winner, although at a higher cost. 

Conversely, if ease of maintenance and affordability are crucial factors, VG10 remains a compelling option, offering a well-rounded performance that should satisfy the needs of most knife enthusiasts.