Steel Question

[Confederate]

I've been trying to get a grip on the various steels in folding knives and thought someone could help me.

First, is there any difference between Cold Steel's AUS8A and AUS8? I've bought a number of knives made by Cold Steel and have found their heat treat to be outstanding. AUS8A is easy to sharpen and holds an edge pretty well from my experience. But what is YOUR experience? A number of years ago, CS made a number of knife blades from 440A, a pretty miserable steel when provided by other manufacturers. But I have a few knives, including a Night Force and a Recon 1, that sport 440A blades and they're much better than I expected. (I still carry my Recon 1 on occasion and except for its weight it's an excellent knife.)

How does AUS8 compare with VG-1 and VG-10? How many clicks up is VG-10 from AUS8? And how many clicks up is S30V from VG-10? I have a Spyderco Native with an S30V blade, and while it certainly holds an edge better than AUS8, the difference isn't as dramatic as I'd thought.

When using a Spyderco Sharpmaker, should the higher grade steels be sharpened with the rods set for 30º, or should they be set for 40º?

Thanks for your replies!

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[RevDevil]

This can be a pretty lengthy topic. As far as AUS8, it is a Japanese steel. My guess is that the foundry or foundries that make it use the same recipie to achieve the raw material. Now whether Cold Steel or SoG uses it, makes no diffence, it's still the same formula, the differences come in by way of the heat treating and tempering processes used which can vary widely.
Another couple examples, S30V is the exact same thing as CPM-S30V. Wy some companies choose to use the one name over the other is unclear. However, 154CM is not the same as CPM-154, the difference being in the way the alloy is created. To get even more confusing, there is no such thing as CPM154-CM, it's a typo make by a lot of folks, mostly stores.

Here is some infomration in a handy chart configuration:
http://zknives.com/knives/steels/steelchart.php

 

[knarfeng]

Howdy Confederate,
AUS8 and AUS8A are two names for the same alloy. If memory serves, the "A" stands for "annealed", which is how it is sold by the steel manufacturer.

There is only one manufacturer of AUS alloys, Aichi Steel. 8Cr13MoV is an alloy with similar composition and similar edge retention. I believe there to be multiple Chinese manufacturers of 8Cr13MoV.

If hardened to the same hardness, VG1 and VG10 hold an edge about the same. Both hold an edge noticeably better than AUS8 at the same hardness in daily use.

S30V holds an edge noticeably better than VG1 and VG10 in daily use.

It's hard to quantify alloy performance and say exactly how much better one is than another. Cutting performance is more dependent on the blade geometry than it is on the alloy and differences in blade shapes tend to mask the differences in alloy performance. In actual daily use, the most I will say is whether I can actually notice a difference.