Difference among Aus 4 and Aus 6 and Aus 8 steels

[Folderguy]

Has anybody quantified the differences in edge retention among the Aus steels? If one goes from Aus 4 to Aus 6, how much better is the Aus 6?

Same thing for Aus 8. How much better is it than Aus 6?

And in the "real world" what kind of difference would one note between the steels?

Thanks,

Folderguy

 

[knarfeng]

best I can do is comment about AUS8 and AUS10 and then extrapolate.

AUS8 takes a finer edge and is easier to sharpen at about the same hardness.
AUS10 holds an edge better. Enough better so that I can tell the difference in everyday use.

I would expect AUS4 and AUS6 to both take very fine edges, possibly finer than that of AUS8, but not noticeably different from one another. I would expect to notice the difference in edge retention between the two in every day use, if both were hardened to the same hardness.

 

[orca8589]

I think the main differences are in carbon content. In short, AUS4 might be the easiest to sharpen, but won't hold an edge as long as the others. AUS10 might be the most labor-intensive to sharpen, but would hold it's edge a lot longer. Quality & Durability of any of them would depend on heat-treat.

I have no knives in AUS4; I have a friend here who has a CRKT with it and he won't carry it anymore. He had to sharpen it almost daily.

I have an old Kershaw 1060 Black Horse in AUS6, and it would take a great edge, freehand, and it would hold it about as long as my old U.S. Schrade LB7. I'd put my old Schrade to the stone about once-twice a month.

I have several CRKT's in AUS8, and they're a little better, but not by much. I would think that AUS8 would be at least noticeably better than AUS6. It may be the way CRKT has the blades made & heat-treated, I don't know. These were my outdoor knives, so I ended up sharpening them to a more obtuse edge since a finer edge would be at risk for chipping. CRKT's AUS8 never chipped on me, but I was very careful with it, too. (Pruning, etc.)

And last, I have a Spyderco stainless Native in AUS10, combo-edge, and I've only sharpened it once, after six months of general (light-to-medium) use. It takes and holds a really nice edge. As far as I know, Spyderco is one of the only mfrs. using AUS10.

Hope that helps.

~Chris