A2 vs 5160 -- opinions?

S

storyville

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Aug 11, 1999
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These two steels appear well-suited for similar blade designs and uses. Assuming good heat treat for both, is one "better" than the other in some/most/all respects? Why?

Thanks,
Glen
 
On paper, A-2 holds an edge longer and 5160 is tougher. You can't say one is better than the other unless you talk about how you are going to use it.
 
A2 is more wear resistant and 5160 has a higher impact toughness. A2 is also stronger and more corrosion resistant. What difference do these things make? A few examples :

Mission's A2 is left fairly soft and has a decent toughness. I used a MPK for a long time chopping on hardwoods, I would see no chips, however because of the relatively soft RC it would indent readily and I would get a few dents with each session.

Reeve's A2 is harder and will not dent on chopping hardwoods. I have done repeated sessions and have worn the edge completely down. It will not dent. However at this hardness it tends to chip out readily on hard contacts, such as if you accidently hit a nail head or screw shaft.

5160 is much tougher and because of this can be hardened so that it will not dent on hardwoods, and will not chip on nail and screw contacts. Specifically I am speaking of the 5160 blades from HI, water hardened edges.

One exception would be the older A2 Busse Combat blades, these were supposed to be very tough. However the heat treat process was very long and involved. No experience with them.

I would recommend you discuss this with R. J. Martin. He uses A2 a lot. I would assume the high strength and wear resistance allows him to create the edges he does and produce very functional blades.

-Cliff
 
I have heard of rather elaborate heat treatment performed on 5160 blades. It is common to use multi-quench cycles and even cryo treatment. Differential hardening is also commonly employed with 5160. These things are made easier because 5160 is an oil hardening alloy (some people use water in differential hardening).

I don't commonly hear of such elaborate processes with A2. A2 is air hardening and it takes more sophistication to slow/control the hardening. Multiquenching and cryo treatment may work, but I get the impression that you may not see them in lower priced or production products. I think that some comparisons of 5160 and A2 are comparing very elaborate treatment of 5160 with simpler treatment of A2.

On another note, I like A2 because it takes a very sharp edge that cuts well. I haven't got my ultimate 5160 blade yet for comparison.
 
I've never forged any steel so I wouldn't have the first clue...

And as far as opinions, oh boy do I have them!! But no, not about this.

Brandon

------------------
I've got the schizophrenic blues
No I don't
Yes I do...
 
Cliff,

You didn't mention the thickness difference between the Kukri and the A-2 knives. The only HI I've seen was about a half inch thick at the spine and was more of a long skinny hatchet than a knife. I don't think anything could "chip" the edge, no matter what steel it was made out of. True in this case?
 
Thanks for the replies. Steve: I paired these two for opinions as they are often touted for similar-style knives and for similar uses. Most notably, makers use them in hardcore "choppers" -- which often translates as: this steel can take much more abuse/punishment than steels X, Y, and Z which I also use (e.g., Rob Simonich and Neil Blackwood both generally prefer D2 in smaller knives, and A2 in bigger knives). But some also use them in smaller knives with reputedly excellent results (e.g., CRK uses A2 in well-regarded 4" blades, many bladesmiths use 5160 in small hunters).

Cliff: I’d be curious if you do any corrosion comparisons of the two. A2 is "hypothetically" more resistant due to its higher Cr content (5% +/- vs <1% in 5160), but I wonder how much so in actuality. Here in dry SoCal, I cannot get my HI khukuris to rust w/o making the effort.

Jeff: I think A2 has been more popular partly due to its "simpler" heat treat. Also, interesting factoid which I didn’t know: Cougar Allen noted in another thread that 5160 has only recently become available in "useable" size stock for stock removal makers (i.e., before it came in sizes – like leaf springs – which needed to be forged). But from what I’ve read, 5160 isn’t complicated to heat treat – in fact, many starting makers like it because it allows for a relatively wide margin of error – it simply takes longer, due to the multi-quench/tempering cycles you noted. But apparently it is otherwise a steel which even novices can effectively make into a "first" knife.

What’s the cost difference between the two? I imagine A2 is a bit more expensive, yes?

Glen
 
Storyville, both A2 blades I cited were coated and thus it is difficult to compare the corrosion resistance to the bare khukuris. I did see the Mission's edge rust on occasion, but I never did anything to protect it. The khukuris I clean and oil on a regular basis, if I don't and they are left wet they will take a coat of rust easily. No deep pitting though, it comes off easily with a worn Scotchbrite pad.

Steve, the edges are not that particularly obtuse, while the blades are thick there are no secondary edge bevels. In any case I have used the blades hard enough to overstress them, they just deform and don't chip.

-Cliff
 
I have made many blades out of 5160 and love the stuff. I use the stock removal method and do my own heat treatment. I have both single quenched and triple quenched the steel followed by a cryo treatment with triple tempering. It really is not as complicated as it sounds.

5160 can be differentially heat treated which, in my opinion, makes for a dramtically better overall blade, hard edge - spring temper spine.

A-2 holds a great edge (from what I've read -superb and better than 5160). A-2 is an air hardened steel and since I do not yet own a heat treating oven, I have not used it.

A-2 is way more expensive to purchase in bar stock. About $17 a foot for 1/4" x 1" stock compared to about $1.50 a foot for 5160.

Overall - I would rather have a bowie or large fighter out of 5160 and a skinner out of A-2. A-2 has better edge holding, 5160 better toughness and lateral stress survivability.
 
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