Stainless and High Alloy Japanese Knives
Read about High Carbon Steel in Japanese chef’s knives here.
Alloy steels are generally of a more modern metallurgy than high carbon steel knives and continue to evolve. By adding chromium, molybdenum, vanadium or other elements in different proportions and processes, stainless steels can be manufactured that will not rust if left in contact with water or air.
However, because of the properties of these same alloys, these steels behave differently to alloy-free carbon steels and are manufactured to maximise traits that high carbon steels necessarily lack. As we add more varieties of steel to our kitchen knife range we will add information below.
VG Steels
The VG range of steels is an excellent example of a stainless steel that manages to do away with HCS’s tendency to patinate or rust without removing the complimentary attributes of hardness or willingness to take an edge. JTA currently stocks two ranges of knives made with these steels — our Tamahagane Kyoto range use a thin slice (0.65mm) of VG-5 to form the blade edge, while our Tetsuhiro range’s edges are forged from the popular and ubiquitous VG-10.
VG-10 is a very hard wearing stainless steel that remains easy to sharpen. Of course, these two key qualities have made it extremely popular for use in the kitchen and it is estimated that around two-thirds of kitchen knives manufactured in Japan are manufactured with VG-10 — not bad for a steel forged by one (comparatively) small, family-run company. VG-5 is it’s less well-known sibling, though both retain similar properties.
Each of these steels are manufactured by the Takefu Special Steel Company in Echizen, Fukui Prefecture. VG-10 has a relatively high carbon content of 1%, with 15% Chromium, 1% Molybdenum, 0.2% Vanadium and 1.5% Cobalt. VG-5 has a slightly lower proportion of all of these, and no Cobalt.
The practical difference? Well, to the casual observer, not much. In general terms, each of these steels can be tempered and heat treated in different ways by different end manufacturers to emphasise some properties while minimising others.
As far as our knife ranges go, the Tamahagane Kyoto knives using VG-5 are hardened to Rockwell 61 and so are very hard wearing. They are clad with another stainless steel (SUS410, thanks for asking) which looks absolutely stunning but does not affect performance. In general kitchen use they retain their edge for a long time and keep their looks, refusing to tarnish.
I haven’t been able to find a Rockwell number for our Testushiro VG-10 knives, but I suspect they are not as hard as the Tamahaganes and seem to be ready for a sharpen quicker. However, they are very easy to sharpen — almost as easy as my blue paper steel knives. So for a lower maintenance knife I would recommend the Tamahagane, or if you are looking for a great value knife and enjoy the satisfaction of sharpening, consider the Tetsuhiro.
