by Tony Sculimbrene
July 23, 2014
In today’s knife world, there is a relentless drive towards better steels. S30V, a top choice even four years ago, is now a common steel. The power of powder metallurgy (a process whereby very pure steel “dust” is pressed and heated to create very pure steels) has given steel companies the ability to tweak recipes on a molecular level. This, in turn, gives them the ability to alter a steel’s performance in a myriad of ways. Nearly all of the best steels ever made (in terms of performance) have been made recently. M390, M4, 3V, ZDP-189, S35VN, CTS XHP, and CPM 154 all come tantalizingly close to being “the perfect steel,” each with an impressive array of aspects that make them all very tough, very hard, and very corrosion resistant.
But Yasuke Specialty Steels, a branch of Hitachi, has been chugging along for centuries making a few different grades of steel that all start out with ultra pure sand iron deposits. Long a favorite of Japanese wood working tools (such as these beautiful Japanese axes), these iron sand steels all have very low levels of impurities.
Iron sands have been used in Japanese steel since the time of the samurai, and even in today’s market place, these iron sand steels are still remarkably competitive. Yasuke makes three grades of iron sand steels for Hitachi–white, blue, and Super Blue. Of these, Super Blue is the best performer–very pure with some added chromium to make it more stain resistant. Named for their paper wrappings and not the color of the steel, these iron sand steels are the steels of legend.
Super Blue comes in at 63-65 HRc, which is essentially the same HRc as ZDP-189. It is not quite as stain resistant as ZDP-189 or M390 (another super hard steel), but what it lacks in corrosion resistance, it makes up for in its ease of sharpening. Thanks to a very uniform grain structure, Super Blue is about as hard to sharpen as VG-10, despite its very high hardness. In short, Super Blue competes nicely with the best powder steels despite the fact that it is closely related to steels over a five hundred years old.
Spyderco has recently released a Sprint Run series of their best selling folders with Super Blue steel. Starting with the Mule and going through the Caly3, they finally released a Super Blue Dragonfly 2 in May of this year. Given my love for the Dragonfly 2 design and the impressive performance of Super Blue, it was a hard package to pass up. Here is the review.
Here is the product page for the Super Blue version, which is a Sprint Run (or limited edition in Spyderco parlance). The blade steel here is a laminate with a core of Super Blue steel and sides of 420J. The handle is dove gray FRN. There is an over-the-top, deep carry pocket clip.
Complete article at: http://www.alloutdoor.com/2014/07/23/spyderco-dragonfly-2-super-blue-review/