Differences between the Extrema Ratio ONTOS and the new ONTOS II

 Understanding the Differences between the Extrema Ratio ONTOS and the New ONTOS II

Let's take a look at them!

Above, the mighty Extrema Ratio ONTOS

(Black oxide MilSpec coating)

Seen above here: The New Extrema Ratio ONTOS II (shown is the N690 Expeditions version, there is also a Böhler S600 Tungsten alloy version as well-more on this later) . 

So what's the difference?

In order to understand the difference between these 2 models we will discuss the finer points of the original ONTOS, a knife which is still a current model from Extrema Ratio.

The Ontos was conceived as a hardcore military survival type knife 

and as such it's design reflects this. A Western styled Tanto, which had a convex ground edge placed upon it. The main part of the blade however is not totally straight and has the slightest curvature to it; combine this with a similar slight curvature of the tip cutting section and you have a formidable cutting piece. 

In order for excessive strength capabilities, the blade width is 6mm and a type of sabre grind, with the spine being reduced in two  key regions, (see below)

one just behind the tip to give this model fair to good penetrative abilities despite it's blade thickness. The spine is further reduced in a region after the hilt where alternating serrations have been placed, 

enabling it's capacity to quickly cut cords. The ONTOS is extremely capable of hard tasks and due to it's overall weight can also be used to chop effortlessly. 

Before I go any further, if you have not seen my extensive reviews of the ONTOS over the years then please check them out under the Play list of Extrema Ratio knives @BushCampingTools.

 

The geometry of the ONTOS is thus totally suited for such tasks as chopping hacking, cutting, levering, hammering, skinning and butchering, along with fire starting tasks. With a hand ground convex edge, the knife edge retains good functionality with heavy work on dirty objects and can easily be maintained in the field. 

The Ontos comes with an option to attach a small pouch which one can place a "survival kit" and diamond sharpening plate. I of course got rid of most of the stuff in this tin and replaced it with my own materials. Needless to say it is fully Molle compatible and also features a leg strap and like all of their scabbards there is much attention drawn to the quality of the stitching and robust nature of their design.

Now what about the new ONTOS II?

Above image showing the Böhler S600 version of the ONTOS II

Ok, so other than a name change, I feel the ONTOS II is a totally different knife 

than that of the ONTOS. It has been designed for an entirely different market/end use. (Teflon coated)

For a start, the blade features a full flat grind which by default results in a substantially thinner profile than that of the ONTOS. 

Blade Coatings

There are about 5 different industrial types of Teflon coatings for steel. Of these 5 it is unknown to me at present which formulation Extrema Ratio are using. When i find out i will publish it here!

One notices the blade is lighter in the hand 

and this of course has it's benefits for a knife which is practical to be used all day and not just brought out for an imminent survival situation and or emergency. Plus working with the knife at shoulder height or above there will be less fatigues, simple things like this can matter under some circumstances.

The Blade of the ONTOS II has been re-engineered for cutting tasks. The tip is no longer that of a Western styled Tanto and more of drop point with good curvature which will allow for use as a skinning knife (if you had to). The ONTOS II is not a knife for levering with like the ONTOS, where the full width of the tang/spine proceeds almost to the tip of the knife.

The serrations have disappeared and this region can now be used to break dead wood without unnecessarily dulling the primary knife edge (see my Kizlyar Supreme Survival knife reviews where Kizlyar Supreme also feature such a section on their spine of their survival knife). It is not (as comes from the factory) acute enough to strike a steel against.

They (Extrema Ratio) have however left a good chunk of spine unaltered in order to provide a flat surface for light hammering and or striking surface for a baton. However, the ONTOS II 

is now basically in the large "camp knife" category- yes it can like all large knives be used in a "survival situation but why would you since if you plan to stay on a deserted tropical island (as I have) you would instead choose the Ontos as weight is not a consideration if one is not on the move.

With 2 options available, a N690 "Expeditions" model, equipped with molle/pals compatible sheath and a Malice strapped pouch and fire steel, what more do you want for your camping/hiking trip? Ok, so what more do you want?

How about the S600 Tungsten alloy tool steel version? What on earth are you are talking about??? PROVEN INDUSTRIAL GRADE STEEL!!!

Well here's the scenario, you like going out into the wilderness, you will be cutting stuff, all sorts of stuff and you want to move as light as you can for as long as you can then you may not take a sharpening device with you want an edge which will hold up against the most abrasive stuff you can throw at it like cutting mushrooms close to the ground where there is a high probability of the edge contacting stones etc. 

Then you want to process some wood and the only wood is stuff laying on the ground. This wood will never be as clean and free of dirt like fresh sawn timber or dead wood still on the tree, plus you may not have a choice here. Essentially you are taking a big knife made with a steel, of whose edge will resist damage to a greater extent better than N690 all things being equal. 

Now just imagine that all that dead wood laying around is extremely hard, say for example: Eucalyptus and or acacia wood (found across most of Australia), or other hardwood species elsewhere. All knives can stay sharp when cutting into green live timber but how well will they stay sharp cutting in well-seasoned hardwoods off the ground? The more resistant the edge to dulling (all things being equal) the longer it will stay sharp. That's physics!

 How about camping on the coast for a while and having to cut sand impregnated marine ropes washed ashore? Gutting fish all the time etc. The higher the HRC the longer that edge will stay sharp.

Now you are saying, heck why no just harden N690 to over 60HRC? Well if one does this, any stainless properties will go out the window because the higher the HRC for N690 the less resistance it has to corrosion and heck that's why you would choose N690 for such a knife if you plan on working in wet/damp conditions all the time and not a high probability of keeping the blade dry, then this might be the case just to use a HRC 58 knife. That being said, S600 is not as resistant to corrosion, and one should keep it dry. 

So where will S600 shine? 

Firstly, let me say the S600 is an industrially proven steel alloy routinely used as cutting cutting tools for the hardest of materials in high speed tooling.

It is capable of being hardened to very high Rockwell values and retain it's toughness characteristics. Where as many steel alloys can be given a high Rockwell value, not all are actually designed for such high values without a compromise to overall toughness loss and hence a increase in brittleness. For example: Crucible (CPM) did not recommend a HRC range above 60 for 3V but Benchmade for example created knives with HRC greater than 60. I'm certain there are trade offs here with decreased toughness and this is exactly what CPM indicated. So here we have with Böhler's S600, a tool steel designed to be hardened right up to HRC67!

So back that question, where will S600 shine?

Just one of many examples might be: in dry dusty (and hence abrasive) environments 

(and as mentioned above re cutting seasoned hardwoods), where little or no water can be wasted just to sharpen a knife. So in other words an arid/desert (as an example but of course not limited to) environment. So one's knife edge needs to stay sharp for longer in between being able to actually put it against a stone/device. 

There are of course trade offs with all high HRC knife steels and that is it will, by physics, take longer to sharpen compared with a lower HRC56-58 hardened and tempered blades, especially if carelessly allowed to go blunt. With S600 it has a proven edge stability-after all it is a tool steel which is used to cut other metals including other steels!

So if you don't know, what is in Böhler's S600?

So taken directly from Böhler's site (remembering here they are talking about these features in relation to cutting metals- NOT organic materials).

Just look at that elemental composition! It is of course the high Molybdenum (Mo), Vanadium (V) and Tungsten (W) percentages which give the S600 it's amazing characteristics and partake in carbide formation with the Mo also contributing to the overall toughness.  S600 is an alloy which can of course be hardened in the vicinity of HRC 65-67! at a tempering temperature of 540C, however, in the case of the Extrema Ratio ONTOS II S600, we have a more respectable and practical HRC of approx: 64, which is super hard but not insanely hard!  The S600 has also been cryogenically treated for optimal grain structure. Vanadium carbide generation and WC generation provide the basis for wear resistance with Mo improving the toughness.

More to come in the field so stick around!

BCT

MORE here!

This conclusion taken from the following Journal:

Journal of Materials Research and Technology

Volume 26, September–October 2023, Pages 6462-6475

Please note that the alloy in question is NOT S600 but AISI M2 which is the closet equivalent to Böhler S600. 

The austenitization temperature is the most influencing variable on toughness.

When accompanied by a proper combination of austenitizing and tempering cycles, the CT contributes to the enhancement of the impact toughness and the wear resistance of the AISI M2 tool steel.

The selection of 1185 °C for austenitization, 520 °C for tempering, and the use of Cryogenic Treatment is an excellent option to improve the Toughness of M2 steel.

The selection from 1185 °C to 1200 °C for Austenitization, 520 °C for tempering, and the use of 28 h Cryogenic Treatment or even higher is a good option to improve the wear resistance of M2 steel.

Cryogenic Treatment allows improving both wear resistance and impact toughness.