Miyabi 7000 D Chutoh


From top to bottom :

Product description :

Following in the tradition of master craftsmen who produced the famously sharp and incredibly beautiful Japanese swords, MIYABI knives from J.A. Henckels feature authentic Japanese blade designs, extraordinary sharpness, and perfect balance. They're endorsed by Rokusaburo Michiba, the legendary Iron Chef, who understands the importance of a sharp knife for preserving the taste and texture of delicate foods. This mid-sized Chutoh knife from the MIYABI 7000D series is ideal for cleaning, cutting and carving all types of fish and meat. MIYABI 7000D knives are constructed with 32 layers of steel wrapping a core of CMV60 stainless steel that's wrapped in a stunning Dsamask wave pattern. The special CMV60 steel has an incredibly resilient core, with cobalt for corrosion resistance, molybdenum to enhance hardness, and vanadium to help bond the materials while allowing the blade to hold its sharpness. The symmetric blade is finished using the traditional Japanese Honbazuke honing treatment that provides a lasting scalpel-like sharpening and 19-degree cutting edge.

The traditional D-shaped handle offers excellent finger-tip control and is made from stainless steel and micarta--a multi-layered synthetic compound of linen and synthetic resins. Wash the knife under running water with a mild soap, and thoroughly dry before storing in a dry place. To avoid corrosion and damage, it should not be cleaned in a dishwasher. MIYABI 7000D knives should be professionally sharpened or sharpened at home with a wet stone due to extreme hardness at 60 Rockwell. It's backed by a lifetime warranty. Made in Japan.

And from the manufacturer :

Fascinating blade aesthetics because of the multi-layered steel with its attractive Damask design.

Japanese cuisine values aesthetics highly. These are the knives that complement the demanding presentation of Japanese dishes. The blades are made from top-quality steel with 65 layers and impress with their fascinating Damask design. The specific blade construction allows for the high hardness and therefore outstanding sharpness and cutting edge retention of the MIYABI 7000D knives.

Steel with 65 layers and a core of top-quality CMV60 stainless steel, containing cobalt, molybdenum and vanadium for additional strength and durability of the blade. The high carbon content allows for a hardness of approx. 60 Rockwell and therefore exceptional sharpness and cutting edge retention. The final sharpness is applied by the original Japanese Honbazuke honing that is carried out by skilled master craftsmen using a fine whetstone and elaborate hand crafting.

Fascinating aesthetics of the blades because of the multi-layer steel with an attractive Damask design.

This review consists of :

Specifications

The Miyabi Chutoh is an entrance from Henckel's into the Japanese style lines of knives. A few specifications :

More on the grind, it has a low convex grind which transitions into an edge which is right chisel ground about 10:1 (the right bevel is ten times as wide as the left bevel).

Initial impressions :

Initial Sharpness

The Chutoh was slightly damaged as it was bought used. It was a display/show model and had the following issues :

The picture at the right shows a portion of the damaged section of the blade which shows the rolled section as the lighter section on top of the edge. Note this is at 50X magnification so the damage was restricted to blunting it was not significant damage and just ensured the knife required a sharpening before use.

Kitchen

As medium sized blade, basically a small and narrow chef's knife, it had a very wide scope of work. As with all knives with a dropped blade, it could work well to a cutting board for typical dicing and slicing, and the very thin convex grind produced high cutting ability. Typical vegetables :

were all handled well, and the convex grind did improve resistance to sticking (as the convex curvature breaks the point of contact with the blade and the food in the cut).

However the thinnest of the grind was not so restrictive that it could not be used for any bone work. It was used on poultry and some fish and the only restrictions were that the very heaviest of the work, removing the knucles, was done by breaking the bones vs cutting through them. The weight of the knife comes in use at that point.

As it is a mid sized knife it can also be pressed into service for some more delicate work, usually reserved for a paring knife. Can it replace a paring knife in general - no. It is a lot heavier and awkward to turn but for a small amount of work, it is functional compared to a much larger full size chef's knife which would be much more akwward.

It mainly came down to the volume of work being done :

but beyond that, a decent paring knife would be used to simple reduce fatigue. But for smaller amounts of work, or when precision wasn't that required, it is easy to see why this size/class of knife gets popular for a one-knife type approach as it is so versatile. It only really starts to become awkward on larger fruits and vegetables (turnips, melons, squash) where it doesn't have the blade length to allow full cuts.

On smaller cuts of meat :

It was again a very functional size and efficient in such work. Similar to being problematic on larger fruits and vegetables, on full size roasts and larger cuts of meat, a full size Chef's knife (or dedicated slicer) tends to be much more functional.

The same kind of performance paradigm was seen when using the Chutoh as a bread knife. On small multi-grain loaves it works well, provided of course it is properly sharpened. But on large loaves of bread it simply doesn't have the length required to make full slices.

As a point about sharpening and cutting bread (or a tomato), there is a popular misconception that edges which highly polished can't do either but this isn't the case. Now it is true that highly polished edges don't have high edge retention in slicing, 1 but if there is a problem with the initial cutting ability it is likely due to the apex of the edge being rounded, most likely from stropping or from finishing with a very muddy stone.

Grip

Comfort : The only issue with the grip in regards to ergonomics is that in a forward grip the thin heel of the blade is a bit squarish. However in general the knife cuts so well that this isn't a significant problem even in extended use. However it would be nice to see it rounded especially considering the price. Ironically the spine is rounded which is less of a contact point than the heel of the blade.

Security : The grip is fairly slick and does not have very much retention if the grip is compromised with oil or blood. However the cutting ability is so high in general that it is not a significant issue in most use aside from using the knife to do something outside of normal use such as filleting fish. However even such cases the dropped blade acts as a guard and prevents ramping up onto the edge.

A big contrast can be seen comparing this grip against the Chicago Cutlery Chef's knife which has a much more squarish grip which in general gives it much more security and really locks it in and prevent it from rolling in the handle but does have significantly less comfort for the same reasons. The Farberware Chef's knife which has a bit more texture to the grip as it is rubber like and also has a much more tapered profile (much wider than it is thick) which both increase security. However the rubber like grip does have many durability concerns.

Durability : The handle is made from stainless steel and Micarta so is basically immune to concerns for most kitchen knives. It can withstand exposure to direct flame and extreme heat to extended periods of time. It is next to impossible to cut the handle through accidental contact and even extended very rough use such as contact with other knives and kitchen utensils will have little effect on the handle aside from minor scratches.

Cleanup : The handle does not absorb grease, oil, blood or any juices and is next to trivial to clean. The only issue is that there are a few little squares cut out of the front of the grip and they are lightly recessed and they can trap some materials and need a bit more attention to remove.

Steel

VG-10 is an interesting steel to use in a kitchen knife as it is a high carbide, high wear steel which excels in cutting abrasive materials. It doesn't have the properties required for either very high corrosion resistance (dishwasher safe) or edge retention at very push cutting sharpness (apex stability). However both of these drawbacks are only so at rather extememe positions.

As an example of the kind of viewpoint needed to see these differences, the Chutoh was compared to a very similar Japanese utility knife in pure carbon steel, optimized for sharpness and apex stability. Both knives were sharpened at the same angle (20 di) and finished on Spyderco Ultra-Fine benchstone, three trials were made in total. The average result, measuring the sharpness by push cutting Esprit baisting thread (six measurements per trial) :

In short, the pure carbon steel blade could achieve an almost 50% sharper performance. Now in terms of what this actually means, the Chutoh will still :

But it will not : In comparison the Japanese utility will do both of those. There are also stainless steels which have the same ability to take very high levels of edge sharpness such as 12C27, AEB-L, 13C26, etc. . Now to be clear, it is possible to make VG-10 that sharp - it just takes more time and effor to stabilize the apex. It is simply much easier with a steel which has inhernet higher apex stability.

Aside from using the knife in the kitchen, it was also used for various stock work, including some utility cutting :

Materials cut :

In terms of raw cutting ability the Chutoh easily outperforms a standard Mora due to the very thin and acute edge grind and there was no significant effect on the edge, no deformation, chipping or wear.

As a more extended check on edge retention the Chutoh was used for some carving on pine. Approximately one thousand slices were made using medium force (30-50 lbs). This was mainly to see :

There was very little effect on the edge, it would still slice newsprint extremely well and the only influence was that push cutting required a slight angle to start. There were no chips, rolls, or even any significant wear.

Now to be clear, pine is a soft wood, not very abrasive and this kind of work can only check to see if there are obvious problems with the steel as any decent knife will have the same results.

On Cardboard it performs as expected for a high hardness, high carbide steel as expected. 2 . It is ahead of steels such as :

and behind steels such as :

In regards to sharpening. VG-10 at 60 HRC is harder to grind than steels such as AEB-L or typical carbon steels, but the difference is much smaller than seen in common very high carbide cutlery steels which now include exteme alloys such as S125V and alloys such as 121REX which are boarder line even steels.

As an example of a typical sharpening after some kitchen use :

The only time where the grindability was seen to be problematic was when it was sharpened with some very slow cutting natural stones. Typical Arkansas stones for example are much more suited to steels such as 14C28N compared to VG-10.

Overview

In short this knife is fairly expensive for a production knife, which is related to the aesthetic nature of the design and it is fairly weighty and handle heavy. However aside from that, it is a solid example of a medium size chef-style knife which can work very well over a broad scope of work and is a solid example of a high hardness, high carbide stainless steel.

Comments and references

Comments can be emailed to cliffstamp[REMOVE]@gmail.com or by posting to the following thread :

The pictures in the above are in the Miyabi Chutoh PhotoBucket album.

1 : Influence of edge grit (finish) on edge retention slicing half inch hemp

2 : Edge retention slicing cardboard, 15 dps DMT micro-bevel


Last updated : 21/01/2015
Originally written: 11:29:2011
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