At a glance
Relative to the other steels on this site. Hardness 65-67 Rockwell C as typically heat treated.
ZDP-189 is the hardest steel you will commonly find in a Japanese kitchen knife. It is a powder stainless made by Hitachi Metals, now called Proterial, and it is usually heat treated to HRC 65 to 67. That is a full step above SG2 and several points above VG-10.
What ZDP-189 steel is
It is a powder metallurgy stainless with very high carbon and high chromium. The high carbon forms a large volume of hard carbides, which is where the extreme edge retention comes from. Like SG2, it is almost always used as a core laminated between softer stainless layers. The cladding keeps the knife from being brittle across the whole blade and makes thinning easier.
How a ZDP-189 knife behaves
Edge retention is the best on this site. A ZDP-189 blade can go a long time between sharpenings in a home kitchen. The cost is on the stones. It is the slowest steel here to sharpen, and a coarse diamond plate helps a lot. At this hardness the edge is brittle. It does not roll, it chips. Board choice, cutting technique, and the food you cut matter more than with any other steel. Rust resistance is good.
Who makes ZDP-189 knives
ZDP-189 shows up in small runs from Seki and Echizen makers rather than in large standard lines. Availability comes and goes, and prices usually start around $200 and climb past $400 for a gyuto, moving with the yen. We do not keep a ZDP-189 knife in our catalog right now, but we can source one on request. Browse the full knife catalog for what we list today.
ZDP-189 vs SG2 and Aogami Super
| Steel | Type | Typical HRC | Edge retention | Rust |
|---|---|---|---|---|
| SG2/R2 | Powder stainless | 62-64 | High | Resists |
| ZDP-189 | Powder stainless | 65-67 | Highest | Resists |
| Aogami Super | Carbon | 63-65 | High | Rusts |
ZDP-189 vs SG2 is a question of how far you want to push. SG2 is nearly as long lasting for most cooks, easier to sharpen, and less chippy. ZDP-189 vs Aogami Super pits stainless against carbon at similar hardness. Aogami Super sharpens more easily and takes a keener edge, but it will rust without care. See our carbon vs stainless guide.
Who should buy ZDP-189
It suits experienced sharpeners who hate sharpening often and cut mostly vegetables and boneless protein on a good board. It is a poor first Japanese knife. Beginners get more from VG-10 or SG2, as covered in our beginner guide.
Maintenance
Hand wash and dry. Use end-grain wood or soft rubber boards only. Never use it on bones, frozen food, or hard rinds. Avoid honing steels. Sharpen with a coarse diamond plate or hard synthetic stone, then finish on 3000 to 6000 grit. Our whetstone guide covers the basics.
Downsides
ZDP-189 is expensive, slow to sharpen, and the most prone to chipping of any steel we cover. Repairing a chip takes real time on the stones. Its extra edge life over SG2 is real but smaller than the jump from VG-10 to SG2, so many cooks will not feel the difference day to day.
If you want a ZDP-189 knife or want to talk through whether SG2 would serve you better, send us a request and we will check what makers have available.
Frequently asked questions
Is ZDP-189 better than SG2?
It holds an edge longer and runs harder. It is also harder to sharpen and more likely to chip, so better depends on whether edge life matters more to you than easy upkeep.
Can you sharpen ZDP-189 on normal whetstones?
Yes, but it is slow. Many owners add a diamond plate or a hard synthetic stone for the coarse work, then finish on regular water stones.
Does ZDP-189 rust?
It has a very high chromium content and resists rust well, though it can stain slightly if left wet with acidic food.