Elmax vs M390 Steel

Elmax and M390 are both highly alloyed stainless tool steels produced via powder metallurgy processes by Bohler.

M390 steel was originally created by Bohler and is also produced as 20CV by Crucible and 204P by Carpenter.

M390 exhibits slightly better edge retention and wear resistance compared to Elmax, owing to its higher overall carbide volume and the presence of hard vanadium carbides. 

Elmax on the other hand exhibits slightly better toughness and ease of sharpening when compared to M390 steel.

Elmax vs M390 Steel At A Glance

Hardness

Elmax and M390 stainless steels exhibit similar high hardness levels, which is beneficial for different types of knives. 

The documents indicate that Elmax steel can achieve a maximum working hardness of around 62 HRC, although production knives are typically in the 60-61 HRC range. 

Similarly, the M390 steel tempering chart shows that it can reach hardness levels of up to 64 HRC, with the recommended range for highest wear resistance being around 58-62 HRC.

The high hardness of these two powder metallurgy steels contributes to their excellent wear resistance and edge retention

Toughness

Elmax steel exhibits slightly better toughness compared to M390 steel, although the difference is minimal.

M390 steel toughness is relatively low, primarily due to its high carbide content and relatively coarse microstructure with larger carbides.

This results in reduced impact resistance, making M390 knives more susceptible to potential chipping or breaking, especially with thin edge geometries or when subjected to high stresses or impacts.

In contrast, Elmax, has a slightly lower carbide volume, contributing to marginally better toughness.

However, it’s important to note that the difference in toughness between these two stainless steels is minimal, and both are considered highly wear-resistant and suitable for most knife applications.

The slightly better toughness of Elmax blade steel may provide a slight advantage in terms of edge stability and resistance to chipping or breakage, particularly in knives with more aggressive edge geometries or intended for heavy-duty use.

Nonetheless, proper heat treatment and appropriate knife design play a crucial role in maximizing the performance of either blade steel.

Edge Retention

M390 demonstrates slightly better performance in edge retention and wear resistance compared to Elmax.

Bohler CATRA Edge Retention Test results show that M390 at 61HRC scored 958.6 for Total Cards Cut (TCC), while Elmax at 62HRC scored 930.7, indicating M390 superior edge retention capability.

M390 steel edge retention is slightly higher than Elmax steel due to its higher overall carbide volume of around 22%.

M390 blade steel marginally better edge retention translates to longer lasting knives that require less sharpening, enhancing the overall performance and longevity. 

However, it’s important to note that both Elmax and M390 are considered premium steels with exceptional edge retention and wear resistance, outperforming many conventional stainless and tool steels.

Corrosion Resistance

Bohler M390 steel and Elmax steel are stainless steels with excellent corrosion resistance.

However, M390 steel exhibits slightly better corrosion resistance compared to Elmax steel, owing to its higher chromium content.

M390 scored very well in corrosion resistance testing, better than several other high-end stainless steels like S30V, S35VN, S90V, and SG2, and outperforming Elmax as well.

M390’s relatively high “chromium in solution,” which is the primary factor controlling corrosion resistance apart from molybdenum and nitrogen, contributes to its excellent corrosion-resistant properties.

In contrast, while Elmax has good corrosion resistance due to its unique chemistry and powder metallurgy process, its corrosion resistance is expected to be slightly lower than that of M390.

M390 knife steel slightly superior corrosion resistance translate to better resistance against corrosion and staining, especially when exposed to harsh environments or corrosive materials. 

Ease of Sharpening

Elmax steel has an advantage over M390 steel in terms of ease of sharpening, particularly when using aluminum oxide abrasives.

Elmax steel is slightly easier to sharpen than M390 steel due to slightly lower volume of carbides, additionally M390 has more vanadium carbides which are typically very hard to sharpen.

The difference in ease of sharpening between these two steels is relatively small, especially when using diamond or cubic boron nitride (CBN) abrasives, which are harder than the carbides present in both steels.

Additionally, factors such as edge geometry, sharpening technique, and the specific abrasive used can also influence the ease of sharpening for any steel grade.

Final Thoughts on Elmax vs M390 Steel

In conclusion, M390 demonstrates slightly better edge retention, wear resistance, and corrosion resistance due to its higher chromium content and overall carbide volume. 

Elmax stainless steel combination of good corrosion resistance and high abrasive wear resistance, coupled with its finer microstructure, that results in marginally better toughness makes it a well rounded steel.

From my perspective, if I had to choose between these two premium steels for knife applications, I would lean towards Elmax.

Despite its slightly lower corrosion resistance compared to M390, the difference is minimal and unlikely to be noticeable in day-to-day use.

Furthermore, Bohler Elmax slightly better toughness can be advantageous for knives, reducing the risk of chipping or breakage, especially in more aggressive or demanding scenarios.

Additionally, Elmax ease of sharpening with soft abrasives, relative to its level of wear resistance, is a noteworthy advantage.

This characteristic can simplify the maintenance and upkeep of Elmax knives, ensuring they retain their sharp edges for longer periods with less frequent sharpening required.

Lastly, a significant factor in my preference for Elmax is its potential cost advantage over M390 premium steel.