This review consists of :
Spyderco ad copy :
Farid Mehr is a British custom knifemaker best known for his heavy-duty, hard-use knives. His first collaboration with Spyderco, the K2�, is a generously sized folding knife that definitely supports the designer�s reputation. Just shy of 10 inches (254mm) overall, it features a 4.53-inch (115mm) blade ground from CPM� 10V��the first high-vanadium tool steel made using Crucible� steel�s Powder Metallurgy process. CPM 10V�s toughness and machining characteristics are comparable to D2 and M2, but it�s impressive 9.75% vanadium content gives it extreme wear resistance. In a knife blade, this translates to superior edge retention�a highly desirable quality for a hard-use folder.
To balance the strength of its broad Bowie-style blade, the K2 features a full-flat grind that tapers over its entire width to a keen PlainEdge� cutting edge. The blade�s spine is also precisely radiused near the handle to provide a comfortable bearing point for the thumb and a Trademark Round Hole� ensures positive one-handed opening.
The K2�s handle is also a study in strength. It consists of two extremely stout scales machined from solid titanium. The reverse scale forms the foundation of the knife�s sturdy Reeve Integral Lock (R.I.L.) and faithfully includes Farid�s signature serpentine cut on the lock bar. A stainless steel pocket clip attached near the pivot pin supports convenient right-side, tip-down carry.
Spyderco�s K2 combines the durability and heft that characterize Farid Mehr�s custom knives with the refined details that define Spyderco�s commitment to reliable high performance.
From Spyderco :
length overall 9.99" (254 mm) blade length 4.54" (115 mm) blade steel CPM 10V length closed 5.45" (138 mm) cutting edge 4.25" (108 mm) weight 6.2 oz (176 g) blade thickness 0.138" (3.5 mm) handle material Titanium
A few details on this one :
In some more detail on sharpness :
This is typical of a high carbide steel which has the edge ground with a coarse grit and then a buffer to finish by applying the apex. The very low grindability means the apex still has the irregular nature of the coarse grit and doesn't fully take the finish from the buffer.
A few initial observations/comments :
The last is dramatic with the handle given a hard squeeze. The grip is pretty thin (3/8" thick) and while the edges are broken the chamfering is minimal and it really stands out when compared to the the rounded thumb ramp. The first thing which is obvious is how ergonomic the grip would be if the handle slabs were rounded in the same way as the thumb ramp. The clip also prints in my hand very heavily but that is very sensitive to the shape of the hand. It also rides very high to the top of the handle and unfortunately isn't a wire or a milled clip.
A few other immediate concerns/questions :
In general, the response to the knife has been very positive, not surprising given Farid's constant and heavy demand for his custom work. Lots of praise :
However there have been a few consistent issues raised :
And the ergonomic issues with the handle are reported fairly consistently :
I really wonder why a custom knife maker would make a large "hard use knife" with a slim, blocky, pocket knife handle that cannot be anything other than ergonomically sub-optimal for hard use. It makes no sense, you really have to wonder what the knife is actually intended for.
Similar with the extreme upswept tip :
Regarding the upswept blade. From what I recall of history, this is the sort of thing that large daggers in some regions have and certain swords possess (usually of Asian origin) with the idea that, combined with the heavier weight, it'd be a good design to whack people with from horseback. Same as with European cavalry sabers.
The point is, I don't see any application for it in a pocket knife, besides making said knife less useful overall.
While obviously not able to compete with high end specialized kitchen cutlery the K2 well compares to other folders and is functionally superior to many decent examples such as the Paramility.
Folders are often discussed as specialized kitchen tools and while the concept does have problems (such as cleaning and issues with bacteria) there are obvious reasons for interest. In many places carrying a folder is a lot easier than a fixed blade and cutting foods is one of the more common uses. While the K2 obviously isn't a kitchen specific folder it does stand out in many aspects in that regard.
The only real drawback, is that the blade is fairly wide and thus it suffers as a paring knife. It can be used sure, but for such use something like the Air is far more optimal. It is simply far easier to turn in cuts, makes finer peels and easily handles larger vegetables like turnips readily.
The upswept tip also has issues in paring work. It is very awkward to use for removing the eyes out of a potato. Similar for work on the core of an apple, removing the seed and hard inner tissue. The wider blade and severe upswept tip are fairly awkward. However in general, given the other positive attributes on the balance it is positive.
Sure an Air is nicer in paring, however the very short blade is limited and
would struggle on anything side from short cuts. The K2 is much more capable
as a general utility knife. The only drawback is that the raw size can be a
bit of an issue in some places on carry restrictions or in general comfort of
use in regards to public application.
Of course that large upswept tip has one obvious use :
Now not everyone doing such use prefers a very large belly and certainly not upswept tips to the extent of the K2, but it isn't uncommon. When cuts are being made with large draw/sweeping motions it certainly is useful. In that kind of work, leaving the edge with a slightly coarse grit such as the DMT fine (25 microns) is very nice for enhancing the slicing ability. The very large belly, almost 50% of the knife is also very nice for rocking cuts, shearing through the joints in chicken legs/thighs with clean cuts.
The steel has enough chromium that it also doesn't develop a patina readily in the kitchen, however will corrode if left wet for extended periods of time.
The raw size, weight and length of the K2 make it a nice tool to have for brush work. The high cutting ability, enhanced with the edge reground to 10 degrees per side, allows easy cuts through small Alders and similar brush and the heft in hand allows efficient light clipping of the branches. Now yes this can all be sliced off with a smaller knife and even larger pieces can be cut by bending wood and putting it under tension. However the size/weight of the K2 makes it able to perform light chopping which can enable it to do smaller brush work significantly faster.
There is a downside though for this type of work as the steel is a bit of an issue as the grindability is low as is the fracture toughness. While wood in general is pretty soft, natural materials often have dirt on them and this can easily damage the edge. This produces a problematic combination as the edge will chip far more readily than a lower carbide steel and it takes specialty abrasives to remove the chips without a serious amount of grinding time. Thus while the size/weight does offer it some use as a light chopping tool, the steel strongly opposes that type of use.
Now of course the argument could be made that folding knives are not very suitable for chopping and in fact are insensible choices for it. However there are folders such as the AK-47 from Cold Steel which not only have locks which can take such impacts, and have the size/weight to give them the power, but also have steels which have a far greater balance of toughness and grindability. For larger knives with a lot more weight/power, if cutting is not going to be done to use such properties it kind of defeats the point of making them part of the design.
For more general use, one of the large drawbacks is in the blade design, in particular that large upswept tip. Now such designs are commonly used in skinning knives such as the classic Randall Model 22 Outdoorsman :
This is a knife perfect for the professional outdoorsman. It has a 4-1/2" upswept stainless blade that is great for skinning that trophy buck.
On the Farid/K2 the amount of belly is almost 50% of the blade and the last 1.5" of the tip has a very strong upsweep. This does provide the classic skinning design but for a lot of general utility it compromises point work as it makes precision point work awkward and some cutting such as point outline work simply impossible.
But again for skinning type work it has its advantages. In some removal of sod to make a pathway, the large upsweep enhances cutting ability and make the work simpler and easier than a more-inline point such as seen on the Spyderco Vagabond. However similar to the wood chopping, while the design has several advantages the steel really isn't suitable to such work as it takes chipping damage fairly readily and requires specialized abrasives to restore the edge without excessive grinding time.
However that upswept tip, while limiting in a lot of applications :
There are also some areas where the function of the knife is enhanced by the same upswept tip. In combination with the long handle and blade length, the upswept tip allows rocking cuts on cutting board and similar style cuts. In the kitchen this has obvious use for example in trimming herbs, but in general utility it can also be of use such as precision length cuts on cords.
Given the fairly large difference in some of these applications, the suitability of the knife is going to be really dependent on the main scope of work of the user.
The grip is one of the weaker elements of the design due to concerns about ergonomics. While it does have some positive elements :
which are not often found on production knives. That fully round thumb ramp in particular is really rare and adds significantly to the comfort. It is not uncommon in small shop knives and is common on all knives from Chris Reeve, but in general for folders that areas is either :
Now there can be use for jimping to add security in hard thrusts, but for general cutting and to allow over hand grips, a full round in that area is much preferred.
It has some problems common with many folders :
They are compounded on the K2 because of lack of chamfering on the slabs. The top part of the slabs has a very light radius but is barely broken and the inside of the scales on the bottom is left almost fully sharp. These combined with the sharp edges on the lock bar cutout make the handle generate a number of hot spots immediately in use when significant force is put into the handle such as common in power grips.
Given the large blade, significant stock thickness and just the raw size/weight then it is obvious this isn't designed for light cutting like the Spyderco Air. In that regard having a handle which makes high pressure points readily in heavier grips is a bit odd as it appears to compromises the base design of the knife. Of course it could be argued almost immediately that maybe the knife is designed for use with a glove and it maybe seems yes rather strongly :
However as the lock release bar has no jimping, a fairly small opening (half an inch), and a very slim handle (small gap), it is very difficult to operate with gloves.
The K2 has a integral lock with an over travel pin and has a number of fairly positive aspects :
However there are issues with lock stick which progressed as the lock faces wore. When the lock reached the 75% engagement point the stick was bad enough that it became difficult/awkward to disengage which isn't helped by the fact that the only access is a fairly slick access. This unfortunately isn't an uncommon problem and has been reported by many users :
Sorry to say I had to trade mine away because of the lock stick issue, sadly leaving me sadly without my giant 10V cleaver :(. I just couldn't take the stickiness every time trying to disengage the blade. I liked the design pretty well otherwise!
The main issue, or at least one of the more significant ones is that Titanium on Titanium is subject to galling and adhesive wear. This has lead makers such as Elliot Williamson to use hardened steel inserts on the lock bar face so that it is steel on steel which tends to reduce if not eliminate any lock stick. It also reduces wear and is much stronger in resisting deformation under harder impacts on the blade.
The edge retention of 10V is one of the promoted strong points however edge retention is strongly influenced by the apex angle and grit finish as well. The initial edge retention with the as-boxed finish on the K2 was moderate, able to match the performance of custom in AEB-L 1 . However initial edges can often be compromised for a number of reasons, often as simple as over heating.
In general the edge retention is going to depend on a large number of factors such as :
In general it was found that when burnishing was used there was little advantage to 10V over very simple steels 4 . It was also found that in slicing with fairly low grit finishes (fine DMT), that the highest advantage for 10V was on fairly soft and non-abrasive materials and that as the materials got more abrasive (dirty) that the edge retention advantage decreased significantly and eventually disappeared on very dirty materials 5 .
The reason for this is that on very harsh materials the apex tends to blunt readily by fracture as the actual grit in dirty materials can contain silica and silica-like particles (commonly found in dirt/clay) which are harder than the steel. 10V doesn't have a significant advantage in fracture toughness to other steels so the more this becomes the way the knife blunts the less 10V has an advantage.
However the more that blunting takes place by slow wear, and especially when an aggressive slicing edge is required, then 10V will do well because it has a very high abrasive wear resistance. This knife also has a fairly high hardness (other samples have hardness tested to 62/63 HRC) and thus it strongly resists deformation and rolling.
In general then, if 10V will or won't have high edge retention will strongly depend on the type of cutting and the material being cut.
The low toughness of the steel was apparent when using it for some light brush work as noted in the above. With a 10 degree per side edge bevel and a 15 degree per side apex bevel, it chipped continuously as the mode of blunting. This was mainly carving and some very light chopping, small diameter branches, just a fraction of an inch thick on soft woods.
Now this was with the knife reground including a reduction in edge angle from the as-boxed condition which given the higher angle would have been much more durable. However this angle is within the range of edge angles used on common knives for such work. A typical Mora for example has a 10/11 dps edge and handle such work readily. The higher carbide volume of 10V leads to a greater tendency of chipping at lower angles, or put another way forces a higher angle to prevent chipping and thus reduces cutting ability.
The other concern is that often, especially on thick bark woods, that the wood can be dirty and thus the edge can easily be damaged from that work and in those cases the low grindability is a concern in regards to ease of sharpening.
The low grindability of 10V in general is readily obvious when the knife is used on very demanding work and basic stones are used. For example, when both the K2 and Vagabond were used to remove some sod. Both knives removed ten sections of one foot square sod and then were sharpened on the fine side of a strong bond vitrified benchstone (similar to an India fine). The number of passes required was :
The K2 took ~3X as much work to reset the edge. Similar in grinding comparisons to CTS-XHP using a Suehiro 'Chemical' 320 japanese stone then it took ~3X as long to reset the edge on the 10V/K2 2 . The main issue is that the bond of the stone is too strong combined with the very high percentage of vanadium carbide in 10V. This means that the carbide will wear the surface of the stone which doesn't release fresh abrasive and it goes slick pretty easily.
However in contrast when stones are used which are designed to cut high carbide steels readily (Sigma Power Select II) then the difference that grindability makes is far reduced. For example in comparisons of 10V and 15N20 both knives had the edges reset very quickly with a SPS-II 240X stone. 3 . It still took longer on the 10V but the stone cut the steel so fast that it wasn't a practical difference as the edge on the 10V was reset in less than 30 seconds anyway.
The low grindability of the steel can be also be pretty much completely overcome by using extremely coarse abrasives which have appropriate bond strengths (low). The edge on the right was formed by a TASK garden stone which has an extremely coarse abrasive, ~100 grit and has a very weak bond strength so it constantly releases fresh abrasives.
The combination of both properties produces very high grinding speed which allow it to easily reset the edge on the Farid/K2. It can even change the edge angle in a very short period of time. A couple of minutes is all that is needed to make even a significant adjustment to the edge angle.
Such a coarse stone however will take pretty large pieces out of the apex if the grind is brought right to the apex. There is likely thus a high chance of over grinding and wastage of steel if such stones are used aggressively. The best way to use such stones is in plateau sharpening where the edge is ground until it almost forms an apex and then an apex bevel is formed with a much finer stone. This takes a little care to check the apex during the grinding, but with some practice it allows very efficient grinding speed.
In short :
In general there are a lot of conflicting aspects of the design such as a handle which is great for glove use as it is large but the lock release has no jimping/small cutout which makes it hard to use with gloves.
It seems obvious that the aesthetics/looks in general were chosen as being more important than functionality in several respects and that even light to moderate use would make some of the issues apparent.
Comments can be emailed to Intro = T0.1M
Pictures are in the Photobucket Album.
1 : Initial edge retention, 1/2" hemp
2 : Influence of edge grit finish on edge retention slicing cardboard: 10V and CTS-XHP
3 : Edge retention slicing 3/8" polypropylene rope (used) - 10V and 15n20 (fine dmt and burnished)
4 : Influence of burnishing on edge retention
5
: Differences in edge retention as a function of the harshness of the material cut
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