Performance of A2 Steel?

[MW740]

I would like some info on the performance of A2. How does it compare to D2 and M2 as far as ease of sharpening, edge holding capability, etc.. Does it chip or roll easily? Does it rust easily?

 

[PhoulPlae]

According to Joe Talmadge's Steel FAQ:

D-2
D-2 is sometimes called a "semi-stainless". It has a fairly high
chrome content (12%), but not high enough to classify it as stainless.
It is more stain resistant than the carbon steels mentioned above,
however. It has excellent wear resistance. D-2 is much tougher than the
premium stainless steels like ATS-34, but not as tough as many of
the other non-stainless steels mentioned here. The combination of great
wear resistance, almost-stainlessness, and good toughness make it a great
choice for a number of knife styles. Bob Dozier is one maker who uses
D-2. Benchmade has begun using D-2 in its Axis AFCK.

M-2
A "high-speed steel", it can hold its temper even at very high
temperatures, and as such is used in industry for high-heat cutting
jobs. It is slightly tougher, and is slightly more wear resistant, than D-2.
However, M-2 rusts easily. Benchmade has started using M-2 in one
of their AFCK 710 variations.

A-2
An excellent air-hardening tool steel, it is tougher than D-2 and M-2,
with good wear resistance . As an air-hardening
steel, don't expect it to be differentially tempered. Its
good toughness makes it a frequent choice for combat knives.
Chris Reeve and Phil Hartsfield both use A-2.

Also, this chart might help:

D2 doesn't rust as easily as A2 or M2. I think its corrosion resistance is slightly worse than 154CM/ATS-34 but better than most carbon steels.

 

[Jeff Clark]

A2 is non-stainless and will rust or form a patina much like a basic carbon steel. It works really well at an Rockwell C hardness of around 60 and holds an edge better than most basic alloys at a lesser hardness. It will not hold an edge as well as D2 or M2 hardened up at 62 to 64. It will resist chipping and breaking better than most alloys at 60 RC. It does not resist breaking as well as basic carbon steels at a lower hardness.

I find it easier to sharpen than the other tool steels (D2 or M2). It is fine-grained and takes a nice razor edge. I like it more than M2 which is a pain to sharpen without a diamond hone. For a knife which may impact with bone I think it is better than D2. I think of it in the same category as 52100.

 

[Danbo]

I agree with Jeff on almost everything he just posted. I say almost, because none of the steels at Rockwell 60 are any fun to sharpen without a diamond stone.

 

[db]

I also agree with Jeff. The only thing I can add to what has been already said. I have 2 blades almost the same 1 in A2 rc 60, the other in D2 rc 60. At that hardness the A2 does hold it's edge longer than the D2 seems too. Not by much isn't really noticeable unless you are comparing side by side. As D2 is really my favorite steel A2 is a very good one and could easily be my favorite if I had more knives in it.