What is MC66 Steel?
MC66 steel is a high-end Japanese stainless steel manufactured by Hitachi following the latest Powder Metallurgy technology. MC66 steel name is Zwilling J.A. Henckel’s steel naming of ZDP189 Stainless steel.
MC66 steel contains very high Carbon (3 %) and chromium (20%) in its composition, which gives it excellent corrosion resistance, hardness, wear resistance, and edge retention. MC66 steel is common in most Henckels Santoku and other kitchen knives.
It is worth noting that Henckels has a habit of renaming steels for its own business reasons. MC66 stainless steel as ZDP189 steel is found in most other brands of knives and is not limited to kitchen knives. You can find it in both kitchen knives and pocket knives as ZDP-189 stainless steel due to its excellent corrosion resistance and edge retention.
MC66 Steel Composition
- Carbon C 3.00%: Increases the edge retention, hardness, and tensile strength. It also improves steel resistance to wear, abrasion, and corrosion.
- Chromium Cr 20.00%: Increases hardness, tensile strength, and corrosion resistance of a blade.
- Manganese Mn 0.50%: Increases Hardness, and tensile strength but decreases ductility.
- Molybdenum Mo 1.40%: Increases hardenability by forming strong carbide
- Vanadium V 0.10% Refines grain size in the steel alloy.
- Silicon Si 0.40%: Increases strength and heat resistance.
- Tungsten W 0.60%: Improves hardness iin high temperature.
- Sulfur S 0.02%: Improves machinability.
Properties of MC66 steel
MC66 Steel Hardness
MC66 steel features an outstanding hardness of 65-67HRC as per the Rockwell hardness scale. This level of hardness cannot be matched with any other steel, and it is attributed to the high Carbon and chromium elements in its composition.
Because of this high hardness, MC66 steel offers excellent edge retention and wear resistance even in very challenging applications. MC66 stainless steel edge retention is at par with other premium steels like S110V and CPM 10V steel.
MC66 Steel Edge retention
Edge retention measures how long steel blades maintain sharpness, and it is directly affected by the hardness of steel. With the ability to attain a hardness of up to 67 HRC, MC66 offers excellent edge retention. MC66 knives will serve you for a very long time without becoming dull.
MC66 Steel Wear resistance
Wear resistance is another area of excellence of MC66 steel, thanks to its composition’s high Carbon and chromium. MC66 knives will not easily bow to wear and abrasion even with frequent use.
MC66 Steel Toughness
As a rule of thumb, the toughness of steel reduces with hardness. Therefore, steel can either offer you hardness or toughness but never both, and this is true with MC66 steel. Because it is very hard steel, it features low toughness.
MC66 Steel does not offer the worst level of toughness but it would be best to be careful with the applications you subject MC66 knives to because they chip and break easily.
MC66 Steel Corrosion resistance
MC66 steel shines in corrosion resistance because chromium takes 20% of its composition. Steel requires about 13% chromium composition to be categorized as stainless steel; therefore, with 20% MC66 does an excellent job of keeping corrosion away.
However, every still is capable of rusting if exposed to corrosive environments. If you leave your MC66 knives in water overnight, they will rust after a while. This calls for proper care and maintenance. To protect any steel from corrosion, wash and dry the knives after use, which should apply with MC66 knives.
Sharpening MC66 steel knives
Because of the high hardness level, MC66 knife steel is very difficult to sharpen. However, this does not mean you will never get a sharp edge after the knife becomes dull. It will take you more time, energy, and excellent sharpening tools to get a razor-sharp edge.
The best way to get a sharp edge on an MC66 steel knife is to sharpen it on different whetstone grit gradually. You can start with 1200 grit whetstone then proceed to 3000 grit then to 5000 grit and finally a 10000 grit whetstone while spending more time on the higher grit. You can finalize the sharpening on a leather strop.
If you are a new user, sharpening MC66 will be challenging as it can take more than an hour. Consider taking your MC66 knives to an expert for sharpening to save you the frustrations and possible injuries.
MC66 steel comparison
MC66 steel vs M390 steel
The first notable difference between the two steel types is that MC66 is a product of Hitachi while M390 is a product of Bohler. The steels have an almost identical chemical composition, but MC66 contains more Carbon (3%) than M390 with 1.9 % carbon.
Both MC66 and M390 steel contain 20% chromium which makes them shine in corrosion resistance, however, M390 outperforms MC66 in corrosion resistance. Because MC66 contains more Carbon, it shines in edge retention and wears resistance.
MC66 vs S110V
S110V stainless steel is ultra-premium steel manufactured by crucible industries. It offers better toughness, wear resistance, and corrosion resistance than MC66. However, it is more difficult to sharpen, difficult to work with, and generally expensive.
MC66 vs SG2
MC66 steel is better than SG2 steel in edge retention and wear resistance, this is due to its ability to achieve a higher Rockwell hardness and the availability of higher carbide contents that are extremely hard and excellent for edge retention.
SG2 blade steel is on the other hand tougher than MC66 blade steel and thus makes a better knife that is intended to be used for tougher applications. SG2 is also much easier to sharpen than MC66 due to its reduced wear resistance compared to MC66 knife steel.
MC66 vs VG10
VG10 stainless steel is popular steel among knife makers and users, it is a more well-rounded steel and thus better knife steel than MC66. MC66 beats VG10 steel in edge retention only. In other performance aspects like corrosion resistance, toughness, and ease of sharpening VG10 steel is better than MC66 steel.
Is MC66 steel good knife steel?
Looking at the properties of MC66 steel, we can say that it is good knife steel. With extreme hardness, it offers excellent edge retention and wear resistance. Also, it contains high amounts of chromium and therefore offers good corrosion resistance.
The major downside is that it is difficult to sharpen, but this can be easily solved by using different grit of whetstones. The other downside is that it is not tough steel hence it is more prone to chipping and cracking due to low impact toughness.
My name is Jonathan M, and I’m a passionate Mechanical Engineer, a knife enthusiast, and the author of this website. I have a bachelor's degree in Mechanical engineering with a specialization in material science. I am particularly interested in researching knife steel, knife properties, and brands. I hope you will find value in the articles on this website. Contact me if you have any questions or input!