Knife review : Spyderco Nilakka


This review consists of :

Introduction and Specifications

Maker webpage and basic specifications :

A bit of ad copy from Spyderco :

The Nilakka was designed by award-winning Finnish knifemaker Pekka Tuominen. Tuominen is one of the world’s most knowledgeable experts on the traditional Finnish puukko knife and one of only seven puukkoseppamestari, or “master bladesmiths” certified by the Finnish Ministry of Education. He is an expert at all aspects of bladesmithing and knifemaking and takes great pride in personally crafting every detail of his knives and sheaths. He is also a winner of numerous puukko-making competitions and a member of both the Scandinavian Knifemaker’s Guild and the Finnish Knife Association. Spyderco is honored to work with this incredibly talented craftsman and to share his designs through our products.

The Nilakka is the result of Spyderco’s longstanding quest to translate the traditional Finnish puukko to a modern folding knife. In the spirit of the other knives in Spyderco’s Ethnic Series—and based on the success of Tuominen’s FB28 fixed-blade Puukko design—Spyderco asked him to express the critical qualities of the classic puukko in a folder. Through a collaborative exchange and a number of prototype revisions, the knife gradually evolved into its final form.

The Nilakka’s handle is built on a framework of full-length stainless steel liners that also provide the structure for its Walker LinerLock® mechanism. The liners are joined by a stainless steel back spacer and covered with machined G-10 scales that create the distinctive diamond-shaped cross section that is a hallmark of traditional puukko design. Bead blasted to ensure a secure grip, the scales are extremely ergonomic and allow easy orientation of the edge by tactile sense.

Made from premium CPM S30V stainless steel, the Nilakka’s blade features full-flat-ground bevels that flow smoothly into a zero-ground cutting edge. This unique form of Scandinavian-style (“Scandi”) grind offers exceptional edge geometry for superior low-drag cutting performance. It is accented by a subtle swedge on the spine of the blade and Spyderco’s Trademark Round Hole. In the closed position, the blade is almost completely contained within the handle and the Round Hole nests in a scalloped recess in the obverse scale. This makes the knife extremely trim, yet still allows it to be easily opened with one hand.

A butt-mounted deep-pocket clip supports right-side, tip-up carry, and makes the Nilakka a true “pocket puukko” that is ideal for everyday carry.

Drawing its name from one of the largest and most beautiful lakes in Finland, the Nilakka is a truly extraordinary folding knife that seamlessly combines form, function, and ages-old Finnish tradition into a stylish, modern cutting tool.

A few details on this one :

The image at the right (50X magnification) shows the very slight secondary bevel from the buffer and also clearly shows the large and deep scratches still level from the primary shaping which were not removed.

Fragile edge? - Design commentary

The Nilakka has one of the most extreme grinds on the market, while it is a single-bevel grind, it is very different in one respect from that type of grind also found on the common Mora :

Although seemingly alike, the Nilakka’s full-flat zero grind is very different. This isn’t the same thing as a Scandi or zero-sabre grind which usually terminates at half the width of the blade producing a larger inclusive angle. The Nilakka’s much finer geometry makes for an abnormally weak edge.

How weak or fragile is the knife? A post which started a lot of commentary and discussion :

I mentioned this in the other thread but I wanted this to be where it would be noticed before anybody else screwed up the edge.

I got mine today and went out and whittled a dried sycamore branch in half and it chipped and bent the edge all to hell.

I'm guessing here, but I'm going to have to take back about. 1/32 to 1/16 of an inch to get past the bends and chips.

Don't use this knife to carve any dry wood! Especially don't exert any sideways pressure carving, which is hard not to do.

In response to the feedback which was duplicated by other individuals, Spyderco changed the design and thickened the edge by adding a significant secondary bevel. 1

This increased the strength of the edge and feedback was immediate that the earlier issues with durability seemed to be resolved. 2 However an important point was raised from Spyderco forum member kel_aa :

... Consider how much time it would take a Military (or even a Caly Jr, for that matter) to be ground down to this level by hand and what the knife would look like after. With the Nilakka, you can practically customize the edge on for quite a variety of uses in a few minutes and the primary grind would still be pristine.

With the secondary bevel Spyderco removed this ability of the end user to do this kind of customization - but to be frank, from a warranty perspsective not everyone is going to take this approach and it is not that unexpected to have a knife marketed as a folding puukko be able to cut various woods without immediate damage.

A little experimentation

While it was obvious that there seemed to be durability issues with the knife in regards to even more basic tasks, it was not so obvious that it was all due to the geometry. Kyley Harris noted that one of the factors could simply be that the very coarse grind lines on the primary appear to go right to the apex. There is also the concern that S30V doesn't have high apex stability but the end user can't do anything about that - though it does raise some concerns about design coherence. 3

To examine these issues in a little detail a NIB Nilakka with the original zero grind was used starting with some very light work. As a first check just after some slicing on 1/8" cardboard the edge was visibly damaged.

As shown in the image at the right (50X magnification) the edge no longer has that crisp straight line of the secondary bevel from the buffer but has a wavy appearance and in places the entire secondary edge bevel has been removed. The edge was damaged through :

It thus had effectively next to zero edge retention as the edge was damaged almost at the onset. In addition, cardboard (drilling with the tip) also cracked off about 1 mm of the tip, just using the weight of the knife to drill.

This does seem to indicate a geometry or grinding problem, however there are a number of other influences. The initial edge could have been over heating in the factory grinding and sharpening and/or damaged from rapid water quenching which is also common in power grinding. If this was the case then two things would be expected to happen :

At the right is the result of just two passes into a 1000 grit waterstone to destress the edge. Note :

This is also tended to support for the fact that the edge was damaged by how it was ground as the steel was removed far easier than it should be for a steel which should be both very hard and with a low grindability as S30V has a significant amount of vanadium carbide.

To reset the primary grind and form an apex 100 passes per side on the 1000 grit waterstone clearly apexed the bevel however as noted in the picture on the right a huge burr formed. Now considering that :

That the burr formed under those conditions strongly indicates that the steel had problems as it is cracking apart and deforming rather than being cleanly abraded. This was further supported as the burr would not be cut off even increasing the angle to 45 dps.

The edge was again ground back by making a direct cut into a 3000 grit stone to remove all damaged steel. The edge was again bought to an apex on 100 passes per side on the 3000 grit waterstone using :

This time the edge formed clean.

The edge was then refined on a 8000 grit waterstone :

Now with the coarse primary scratches removed and the apex formed on stronger steel the cardboard cutting was repeated and the performance was as expected for S30V with no visible early on set of damage. The knife blunted as it should with a slow on set of wear and it behaved as expect for a hard and high wear resistant steel with edge retention on cardboard slightly ahead of steels such as ATS-34 and D2.

In short, while the as-ground knife did have some durability concerns, and they are partly due to the very thin grind. They are also influenced by a few other factors :

And two of these factors can be removed by the user by polishing the primary grind and applying an edge with hand sharpening or power sharpening with proper coolants. In regards to general perspective on the steel. This is a very low angle and those kinds of angles tend to be much more functional with high apex stability steels. Forum user "marthinus" has commented on many of the comparisons he has done to show reduced edge damage in high apex stability steels at very low edge angles 5 .

Stock cutting

With an 8000 grit waterstone finish the sharpness was moderate to high :

Some parts of the edge registered as low as 60 grams, on the Espirit approaching the sharpness of an actual razor blade (Gillette Super Platinum) but other parts were over 140 grams. At this point the conclusion might be assumed to be something to do with the carbides in S30V, however the image on the right shows otherwise.

Note the apex line shows a slightly irregular finish which just means that too much of a jump was made in grits during the sharpening and thus the edge ends up to be pseudo polished with some irregularity left over from the coarse sharping grits.

With this finish, cutting 3/8" hemp :

The cutting ability on the 3/8" hemp is really high as expected, the slicing aggression in particular is just extremely high.

Through ten points on on some 1x0.5" pine making 2" points with light force (10-30 lbs) :

The wood cutting performance was also very strong as expected due to the very thin grind. Again this is low force, as soon as heavy force is applied the Nilakka will make a point in just one cut.

In short, given the very thin grind, the cutting performance is very high in shallow cutting where the forces are concentrated around the dge. While the stock thickness is a bit high for utility knives, this will only be seen as a functional drawback when the media being cut can bind on the entire primary grind (like thick foam).

Food

In the kitchen at a paring knife, the Nilakka literally floats through the skin of potatos offering exceptional control with minimal effort. As peeling is shallow cutting it is most dependent on the sharpeness and edge angle mainly, more weakly on the edge thickness and only lightly on the primary grind or blade thickness.

As such the Nilakka exceeds the ability of even dedicated paring knives which typically have edge angles of 10-15 dps and it takes a very high end custom paring knife with a similar edge angle and then slimmer stock to exceed the performance. As such it sets a very high standard for folding knives for such use in the kitchen. In fact the performance is so high that it makes knives which are generally well regarded such as the Paramilitary look poor in comparison.

On deeper cutting, the angle of the edge becomes of less importance (unless it is extreme) and the primary grind and thickness of the blade starts to show its interest. Even though the Nilakka has a very low angle edge, because the blade stock is reasonably thick (0.18") the cutting performance can at best match the Galaxy Cleaver which is on the low end of cutting ability for chopping style kitchen knives but has a stock thickness about a third of the Nilakka.

The problem is that on deeper cutting more of the food "sees" the blade and thus the thickness of the blade behind the edge is critical. In this specific comparison for example the Nilakka is thicker 0.25" back from the edge than the spine of the Galaxy Cleaver so on any cuts which are more than 1/4" deep the Nilakka will start to see a decrease in performance due to the thickness of the blade and this offsets the large advantage of the cutting ability gained by the small edge angle.

This of course is why in general kitchen knives tend to be much thinner unless they are dedicated paring knives or made for shallow cutting or deep cutting on soft materials. The Nilakka is very similar to the David Boye drop point hunters in design :

The Boye hunters thus did very well on meat work, exceptional as paring knives but started to fall behind on utility work and were poor at very deep cutting. They were even thicker than the Nilakka as the spines would be more than 1/4" thick.

On even thicker work, turnip being a common local vegetable, the Nilakka starts to show the downside of the thicker spine more seriously and at this point it is no longer competitive with even the lower end kitchen knives simply because so much of the food is binding on the blade above the edge so the edge is only of low importance. This is one of the main drawbacks of a single angle approach to grinding as it doesn't give the flexibility of a multi-angle grind which allows much more customization in terms of where the thickness of the steel is kept and where it is removed.

For example the Spydero Catherman, which is designed as a folding fillet knife works very well in the kitchen as a general utility and fruit and vegetable knife. While on peeling and other shallow work the Nilakka is superior as again the edge angle is mostly critical for that work, on other work the thinner stock of the Catcherman provides more optimal performance.

General Use

With the knife proving very useful in the kitchen and in light use, it was sent out on loan to YT user Caffeine Junkie for another perspective on the knife and commentary on the scope of work and durability of the zero ground profile. A summary of the video on the right :

In general while the design of the knife was praised for cutting ability, and especially Spyderco's willingness to put out a blade with such extreme geometry, there was obvious concerns about durability with the given profile. Now again this is pretty easy to address by applying a secondary edge bevel and just grinding until the edge thickens enough to prevent any damage.

Now in the video, Cafeine Junie noted that he had concerns about durability and found himself restricting the usage of the knife. With the issues on cardboard resolved with sharpening what kind of durability issues remain? The image at the right which is 5X linear magnification shows what happens when the Nilakka hit a staple cutting open a box, it made a visble notch up into the primary grind. If the knife has a small edge bevel, less than 0.005" at 10-15 dps this damage would have been significantly mitigated.

Grip

Ergonomics : is the weak point of the knife. There are multiple issues with the grip as soon as the knife is given a hard squeeze in hand :

However much attention was given to the design of this knife in terms of appearance but still rounding squarish edges would not remove or lessen that aspect.

Security : this has always been a bit of an issue with puukko style knives which often have very simple handles with no guard. The #1260 Mora is an example of that type of knife. The argument is essentially as simple as don't use a knife to cut in a manner which could put your hand forward onto the blade and you don't need to be concerned about security.

Durability : the handle is made of G10 and steel and there is little concern about damage aside from the regular :

The only way to damage the handle significantly would be to use it as a hammer.

Lock, pivot and clip

The Nilakka has a solid example of a liner lock :

The only concern about the pivot and lock in general is that the pivot screw is actually under the handle slab. While the knife does open smooth, it isn't going to stand out in that regard, especially in an age of thrust bearings and similar focus on action to the extent knives fall open when the detent is disengaged.

The clip, consistent with the design of the knife has straight lines, and is simple to the point of almost elegance. It is a very low ride, flush even, pocket carry which is tip up only. The knife however has a very strong detent so accidental opening isn't likely.

Steel

S30V is an interesting choice of steel for a single bevel grind :

In general steels used for such knives are almost the exact type of steel such as 12C27 commonly used in Mora knives. That class of steel offers :

With single bevel grinds in order to maintain the geometry the entire face plane of the bevel has to be ground down, hence the need for a high grindabilit. With such an approach to sharpening the edge is left with a very thin cross section and therefore a high apex stability is required to keep the edge free of damage. It is hard to see an argument for S30V aside from marketability and it is also much more expensive than such steels both in raw materials and processing costs.

In regards to sharpening, the main issues are :

The two of these combine to make sharpening a bit of an effort as the entire flats have to be planed down each time the knife is sharpened. This combined with the fact the steel is a high carbide (low grindability) alloy makes it a bit of a chore. Most are likely to resort to using a secondary edge bevel and just sharpening that - which is likely to be desired in many cases to resolve durability issues anyway depending on the required scope of work.

In regards to edge retention, in extended trials on cardboard, the Nilakka showed similar performance to other S30V knives. 4

The corrosion resistance was also consistent with other S30V knives as the Nilakka had no adverse reactions to being used in the kitchen on acidic fruits and being left wet for extended periods of time (10-20 mins).

Overview

It has to be noted clearly that this design, like all of the ethnic designs/collaborations that Spyderco does, strongly are focused on the aesthetic design. While this does offer some interesting performance advantages due to the low angle zero-grind, the ergonomics clearly show that performance wasn't really the critical design factor.

This knife had one of the stronger reactions, or at least immediate contentions of disucssion once released due to the extreme geometry and the fact that it was possible to visibly damage the edge even in mild cutting of cardboard and clean (knot free woods). To address that Spyderco modified the design and applied a secondary edge bevel.

In regards to the general characteristics an excellent summary of the Nilakka was provided by the Edge Observer :

Over-all the Nilakka is an interesting offering. It has an immaculate fit and finish and while extremely modern in appearance it still has all the key visual features of its ancestor. While the pivot and locking mechanism are precisely made and robust in build, its blade is unusually delicate out of box and herein lies the fundamental difference: the puukko evolved to be a tough multitasking, easy to maintain cutting tool capable of weathering everyday life all the way from the kitchen to the shop, in or outside. The Nilakka unarguably does not fit this role and Spyderco is self admitted about it’s limited application by a rather lengthy, preemptive disclaimer that comes with the knife.

In short :

An argument can be made that a different steel is more suitable for such a grind, but regardless of the steel used, a zero grind at around five degrees per side has a fairly low strength and thus a limited scope of work, far less than the typical Mora at 10-12 dps which has double the edge angle which leads it four times as strong. There is of course no reason to keep the strict zero-bevel grind and a secondary edge can be applied to ensure the edge has the required strength. If this knife had been initially shipped with an edge bevel between 0.005-0.010" which is typical of grinds from makers who are known for high cutting ability, such as David Boye, then much of the contention about durability would likely have never happened.

Comments and references

Comments can be emailed to cliffstamp[REMOVE]@gmail.com or by posting to the following threads :

1 : A Tale of 2 Nilakka's

1 : SPYDERCO NILAKKA ~ C164GBN - Round 2 - Hard Use Folding Puukko

3 : Edge stability review

4 : Edge retention slicing cardboard, 15 DPS 600 DMT microbevel.

5 : CPM-M4 at low angles.

and/or the YouTube Playlist.

Most of the pictures in the above are in the PhotoBucket album.


Last updated : 17/02/2013
Originally written: 17/02/2013
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