D2 vs MagnaCut Steel

D2 is a non-stainless tool steel, and MagnaCut is a stainless steel specifically designed as a knife steel by Dr Larrin Thomas.

The key advantage of MagnaCut over D2 comes from its lack of chromium carbides, which results in much better corrosion resistance and toughness. 

This gives MagnaCut an advantage for knives where corrosion resistance and toughness are critical parameters. 

While MagnaCut offers improved performance in some areas, D2 remains a popular knife steel due to its long history, availability, and good wear resistance.

D2 vs MagnaCut Steel At A Glance 

Corrosion Resistance

CPM MagnaCut steel is a stainless steel while D2 steel is a non-stainless steel. 

MagnaCut steel has markedly better corrosion resistance compared to D2  steel due to its unique carbide structure.

This gives MagnaCut an advantage for knives that require good stain and corrosion resistance along with wear resistance.

D2 steel corrosion resistance is just “good” for tool steel due to about half of the chromium being tied up in chromium carbides. 

Chromium carbides are detrimental to corrosion resistance. The ranking of steels by corrosion resistance shows D2 in the middle of the pack.

The lack of chromium carbides in MagnaCut results in higher corrosion resistance by avoiding chromium-depleted zones around carbides.

The datasheet for MagnaCut states its corrosion resistance is even better than 20CV stainless steel based on salt spray testing. 

After 72 hours in salt spray, MagnaCut showed no signs of corrosion while 20CV had some light rust spots.

MagnaCut stainless steel corrosion resistance approaches that of premium stainless steels like Vanax and LC200N.

This makes MagnaCut suitable for knives that may see occasional moisture, an important property not possessed by D2.

Toughness

CPM MagnaCut has significantly higher toughness compared to D2 steel.

This difference allows more robust edge angles to be used with MagnaCut, making it better suited for most knife applications especially those requiring high cutting ability.

The datasheet for D2 steel lists impact toughness values of 17-23 ft-lbs depending on tempering temperature.

Longitudinal Charpy C-Notch toughness testing shows D2 with a toughness of around 21 ft-lbs.

In contrast, MagnaCut achieves toughness values of 30-38 ft-lbs depending on hardness. 

MagnaCut has toughness similar to CPM-4V and Vanadis 4 Extra, around 36 ft lbs. Thus MagnaCut has nearly double the toughness of D2.

The much higher toughness of MagnaCut knife steel means it can withstand higher impacts without chipping or breaking compared to D2.

This allows knifemakers to use thinner edge geometries with MagnaCut to maximize cutting ability and edge retention while still resisting chipping, especially important for kitchen and EDC knives.

MagnaCut blade steel’s high toughness also makes it suitable for larger knives where toughness is critical.

Hardness

MagnaCut is capable of reaching higher hardness than D2 steel in the range of 64-65 HRC compared to 60-63 HRC for D2 when optimal heat treatments are used.

D2 steel datasheet shows it can reach hardness levels of 60-62 HRC with a maximum of 63 HRC when properly heat treated.

MagnaCut shows it can reach hardness levels from 60-65 HRC depending on the austenitizing temperature and tempering temperature used.

The higher hardness potential of these knife steels provides knifemakers more flexibility in tuning the hardness to the intended use of the knife.

Edge Retention

D2 steel and CPM MagnaCut have broadly comparable edge retention and wear resistance, though MagnaCut may achieve slightly higher values at high hardness levels.

Both steels owe their good edge retention and wear resistance to high volumes of hard carbides in their microstructures.

The MagnaCut data sheet states its wear resistance is similar to CPM-4V and CPM-CruWear based on CATRA testing. 

The edge retention of MagnaCut steel matched S35VN steel and CPM-4V Steel in CATRA cutting tests.

While MagnaCut demonstrates slightly better wear resistance by some metrics, both steels have high carbide content that lends good edge retention.

At very high hardness levels above 63 HRC, MagnaCut may achieve somewhat higher wear resistance compared to D2 due to its finer carbide size.

However, in the 60-62 HRC range, the two steels have broadly similar wear resistance with neither having a definitive advantage.

Ease of Sharpening

CPM MagnaCut has some advantages over D2 steel in terms of ease of sharpening and grinding.

This can impact the knifemaking process as well as long-term maintenance.

MagnaCut data sheet states its fine carbide structure leads to improved grindability over other powder metallurgy stainless steels. 

Feedback from knifemakers shows that MagnaCut grinds easier than S35VN and S45VN due to its fine carbide size.

It also states that MagnaCut was reported to sharpen well even on aluminum oxide stones.

The finer carbide size of MagnaCut results in easier and faster grinding compared to more coarse D2 carbides.

MagnaCut’s carbide structure also contributes to easier sharpening due to reduced abrasion resistance.

This can benefit both knifemakers and end users in terms of saving time and effort.

Final Thoughts on D2 vs MagnaCut Steel

I believe Dr. Larrin Thomas succeeded in his goal of creating a stainless steel with properties exceeding D2 and other powder metallurgy stainless grades.

By eliminating chromium carbides, MagnaCut achieves a better balance of corrosion resistance, toughness, and wear resistance compared to D2.

For most cutting applications, I would recommend MagnaCut over D2 due to its superior well-rounded properties.

However, D2 remains a viable option, especially for those on a tight budget, as it is significantly cheaper than MagnaCut while still providing good hardness and edge retention.

The initial feedback from knifemakers has been overwhelmingly positive for MagnaCut’s new steel.

I, however, have to note that MagnaCut is a new steel, so many knifemakers have not mastered its heat treatment for optimal properties, I recommend picking MagnaCut knives from reputable knifemakers.