The romanian AK bayonet is made from a carbon steel much cheaper than INFI and it's a few decades old model still in production. You can see the tests performed by Noss on it at knifetests.com and (what I actually want to say) it has extremely high lateral strength. I don't know if it's equal to INFI or lower or higher (have no idea because I didn't see knives with similar sizes and shape tested the same way; however, lots of thicker modern knives failed the body weight test). But in Noss tests you can see this bayonet taking all his weight balancing and passing the body weight test without problems. That's a 3 millimeters thick bayonet and 3 centimeters wide. It broke at the flex test because of that hole into the blade which weakens it. I also have a romanian bayonet older model which was used in World War II and that's also extremely strong for lateral strength. Of course, excepting lateral strength and (maybe) impact resistance, these bayonets are not excelling in other areas. Especially the AK one is very poor at edge retention and rust resistance. But what I want to say is that strong steel existed in the past and few hundred years ago too.

Newdays, knife makers are focusing on optimizing production costs and on obtaining superior edge retention and stainlessness. But for toughness and hard use resistance, after my knowledge, we are unfortunately behind old times as average. There are very few knives today which can really compete with high grade fighting tools that existed long time ago. But the costs are significantly lower today, so that anybody can achieve a good knife, comparing with old times when a good Japanese katana was requiring sometimes 2 or 3 generations of sword makers to finish it. So, of course, I'm very happy I can afford INFI today for just a part of my monthly income and not wait tens of years and pay with a life of work to get one. But that doesn't mean the knives we have today are the best in history.

So my opinion and knowledge is that we are today in the top of the history with stainlessness and edge retention on available knives that are produced today, but not in the top regarding toughness and strength. The really tough knives today are rear and very few. I also think today we have the best quality-price ratio in the history and affordability... and maybe we also have the best all-around knives.

BTW: Very interesting topic!

Regarding DiamondBlades, I found this passage on their site while reading about what makes a good knife (which I can understand is their objective):
"Thus another measure of a high performance blade is one that has a softer tough spine and a very hard edge that is not so brittle as to chip in normal use."

Well, here is the problem and the information which says they are not competing in the area of toughness and hard use knives. I do not consider a knife is tough if it doesn't chip in normal use! And it's also important what each knife manufacturer understands by "normal use". I have used a lot of steels. I have the Fallkniven A2 which's edge at 59 HRC chips while hitting rocks (it chips like glass). And I don't like it because of that! It doesn't chip in normal use. It also doesn't chip while chopping in normal wood. But hitting something harder chips it like glass having pieces of it jumping out of the blade. I suppose diamond blades are excelent knives for normal use. But when talking about the toughest knives in history we are actually talking about more than normal use. Until now, from what is available to buy with money, I only found few blades made nowdays which can hit rocks without chipping (however, they still took some kind of chipping, but which had the shape of the target, so I admit it was more local deforming than glass-like chip). These blades are the Bussekin blades, the SK5 steel blades from Cold Steel and maybe few other blades, but which do not have good edge retention. The SK5 is also inferior in RC hardness (being around 54 compared with INFI at 58-60). So, I keep up my opinion that the technology advantage today is more oriented to improve normal use performance rather than toughness.

I agree. Toughest really is all inclusive. Edge hardness in not related to toughness at all it's separate. Knives/Tools can have extremely hard edges and be very brittle. Toughness is a materials ability to resist breaking it's mechanical, Hardness is it's ability to resist abrasion/wear and strength is it's ability to resist deflection/taking a set. SR77 is just as "tough" as "INFI" but has less wear resistance. Friction forged knives look like they might be good for soft chores such as skinning and such but not for really hard use. Which is OK from there web site it looks like that is the nitch their trying for.

As far as all around toughness I don't think it gets better than Busse at this point in time.

bld522, have you heard of this guy,


http://miltner-adams.com/index.html

i just cant get over that "tough" guy on the website.at least he's the founder/owner of the company and not a model they payed to look tough.he is over doing it a bit though.

miltner-adams was at the blade show last year.i didnt go to their booth though.i have no idea if their knives are any good.i know i dont like the design of their fixed blade.

as far as diamondblades is concerned i dont doubt for a second they are great knives and i'm not calling them weak but imo they shouldnt even be mentioned in a conversation of toughest knives in history.

and when i say tough i mean in general.i dont care what the exact websters term is.you guys no what i mean.i mean FFFBM tough.i mean .320 ASH-1 tough.i mean .285 dumpstermutt tough.there is no way a knife with a spine thickness of 0.118-0.120 can really compete in toughness.will it out cut them??...yes,but we are talking tough.as in bad [censored],hardcore,strong.

lets just give one of these diamondblades to noss and see how long it takes him to break it.i bet it breaks sooner than any knife he has tested yet.

If I had a Diamond Blades knife I would hit a rock with it in full, as I did with my Skinny ASH, with my Bushman and many others to see what happens. If that 65-68 HRC edge would not chip while hitting the rock that way, then I would declare it tougher than INFI and than anything else I've ever tested. And then I will replace my Skinny ASH in my kit with one of their knives if they make a bigger one.

But I can't risk so much money just to test that; if I do that relying just on manufacturer's claims and theory, I have chances to end up as I did with my Fallkniven A2 which I thought it's much tougher than it really is. So I hope I will see some day somebody else doing some hard use tests against a Diamond Blades knife. Until then, there are not enough practical prove to have a real opinion about how tough these knives are.