Blue Steel Super - High Carbon Steel

Blue Steel (Aogami) is a material made by adding chromium and tungsten to White Steel, enhancing the steel's overall resistance and toughness. Among the Blue Steel variants, Blue Steel Super is considered the highest-grade material, in which the amount of carbon and chromium in Blue Steel is adjusted to even further increase hardness and wear resistance.

With a hardness rating of 67 HRC, Blue Steel Super is the hardest of all Hitachi Metals' "Yasuki Steels." It contains not only tungsten and chromium like other Blue Steels, but also molybdenum and vanadium, used in stainless steel. As a result, Blue Steel Super's resistance to wear is unmatched against other steels.

Hardness is crucial for a blade to maintain its sharpness, so the popularity of Blue Steel Super is mainly due to the concept that high hardness equals excellent sharpness. Naturally, if a blade stays sharp for longer, it may feel sharper overall against using other steels over time.

Because Blue Steel Super blades wear down quite slowly as started earlier, they maintain their sharpness for a very long time.

The downside to this is precisely due to the steel’s hardness, it becomes quite difficult to apply a finishing sharpening to the blade with a softer whetstone. Additionally, its hardness also makes shaping and polishing (that is, both making and sharpening) the knife challenging.

Many knives have a blade edge structure that cut by hardness (using a strong small blade), so they can handle even slightly harder foods. This gives blades using Blue Steel Super a little bit more versatility, with some exceptions that we will get into later in this blog.

Steel material is crucial for indicating a knife's initial performance (amongst many other things related to craftsman ability and more). Below are some comparisons to give you some understanding showing what a particular step of the process does in terms of impacting sharpness, balance and maintainability.

There’s three key pointers in the above chart to focus on.

• Steel Material has a large impact on sharpness and maintainability (ease of sharpening and resistance to rust).

• Apart from sharpness, heat treatment and the sharpening process in knife creation also have a large impact on sharpness.

• Measuring a knife’s strengths is more than just its sharpness. Balance and maintainability also need to be considered.

Based on the above steel mapping chart, Blue Steel Super falls in this position on the graph below

Unmatched hardness and wear resistance! All designed for lovers of sharpening.

Let’s look at the tables below and explore the composition of Blue Steel Super more deeply.

In comparison to Hitachi Metals' popular White Steel #2, you can see that Blue Steel Super has a significantly higher carbon content, along with the addition of tungsten, chromium, and vanadium.

Just by looking at the composition alone, you may be able to infer that it will have a robust cutting edge. On the other hand, it leans heavily towards hardness and wear resistance, making it have long edge retention but also making it difficult to sharpen. While other steels can create precise, delicate edges with regular sharpening stones, Blue Steel Super thanks to its well-set tempering, requires significant time to form the structure of the edge using coarser whetstones.

On the other hand, if you find a Blue Steel Super knife that is not that difficult to sharpen in comparison, it is possible that the hardness of that Blue Steel Super knife has been intentionally lowered by using a milder temper or tempering it more. In that case, it seems a waste not to take advantage of the potential of the highest hardness steel used.