"Generally" for a blade around 9.5" or for any blade intended to be used as a chopper or take similar abuse, I would take 5160.
However, it probably comes down to what you intend to do with the knife.
If chopping and similar extreme abuse - 5160
If not chopping, I really like A2.
For most blades under 6" and maybe in and around 6" - 6.5" or so, I would most likely prefer A2.
In both cases for A2 & 5160 (and most if not all steels for that matter) the quality of the heat treatment is still very important.
I don't think you can judge steel quality by composition and name alone. Heat treatment is crucial to any given steel performing well.
I am not an expert on Justin/Ranger knives, but Justin is clearly developing and apparently earning a good reputation for his heat-treatments based on the toughness and performance of his knives.
That said, I have generally noticed a lower than industry average for Justin's fit and finish.
But, if you want a tough, beater knife at a great price that you can work on and work with, Justin's knives seem pretty hard to beat for the money. - Unless compared to Scrap Yard SR-77.
Swamp Rat would be a step up in price, fit and finish in my book. But, SR-101 (aka 52100) isn't likely any tougher than 5160 - probably comparable - not sure - might be close. ?????
*** If you are looking for tough, SR-77 is tougher than either!!! <img src="/ubbthreads/images/graemlins/thumbup.gif" alt="" /> <img src="/ubbthreads/images/graemlins/bowdown.gif" alt="" />
In any event, Swamp Rat and Scrap Yard both have a life-time warranty against breakage. So, Toughness is plenty tough enough.
A2 makes an awesome smaller to midsized knife. For edge holding and ease of maintenance, I would take A2 over 5160 in a smaller to mid-sized knife.
SR-101 (52100) from Swamp Rat is a great steel for most sizes. It may not be as tough as SR-77, but it is plenty tough and holds an edge better. But, Sr-77 costs less.
.....then there's INFI. - If you can afford it, INFI is obviously great stuff.
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