- Victorious : cKc Knives
- Gavac Flipper
- Pretium : Ferrum Forge
- Paramilitary : Spyderco
This review consists of :
Knives :
This review consists of : |
|
This knife is one of Mike's first in his series of flippers and was made oversized. It has the serial number "1" on the back of the flippers.
Maker Webpage : Gavko Knives , basic specifications :
In regards to design consistency, parts of the knife are clearly made or suited for very heavy cutting :
However some aspects of the knife are not so suited for such a design :
Now to be clear these features are common on knives argued for heavy use but they do have some points of concern. S35VN has a fairly low grindability and does not have the toughness of steels such as AEB-L so will take more damage in heavy use and be harder to restore. As well integral lock transfer loads directly from the blade to the lock face which can cause damage under high loads. To combat the latter issue some makers have started using replacement inserts on integral lock faces.
This knife was not intended for sale so it has a few small issues which can be picked with a keen eye and experience with some finely finished knives :
But again this was not intended for sale and was mainly an experiment in function for a personal knife. Even then it shows many of the features common in Mike's knives :
The edge shows Mike's usual finish :
The image at the right shows a fine (high grind) main edge grind with a stropped/buffed finish.
These are very high numbers for initial sharpness, Spyderco for example can not consistently exceed those numbers.
On 3/8" hemp :
On carving wood compared to the #1260 Mora making 2" points on hardwood dowel with light force (10-30 lbs) :
This would be expected as the angle is a bit higher and since the cutting is so shallow the cut ratio should be similar to the angle ratio (11 dps vs 16 dps) which it is (86/110 = 79%, 11/16 = 70%) .
However on deep cutting the performance of the flipper moves ahead relatively due to the primary grind thinning the bevel behind the edge. On some 1x0.5" pine making 2" points with heavy force (50-70 lbs) :
This shows one of the main benefits of the use of a dual grind which is to optimize the geometry and allow the edge bevel to be set at an angle which keeps it stable and free of damage but then use a lower angle to thin the blade behind the bevel to increase cutting ability.
The use of a primary grind also increases ease of sharpening which is of greater importance with the common use of low grindability steels due to the very high carbide content.
In extended use, making 1000 slices,
The cutting ability is very high and the flipper easily shreds wood, stripping off large sections with a greater roughing ability than a standard Mora. However there are issues with ergonomics :
These issues were noted in the initial quick inspection but they become more obvious in extended use. The lock placement issue is very common in integrals and care really has to be taken to prevent a hot spot.
A few miscellaneous materials :
The combination of :
produces a very powerful and versatile cutting tool.
In the kitchen, peeling and other paring work, the knife does well :
and since this is shallow cutting, it is mainly focused on the cross section close to the apex and the thicker blade stock doesn't significantly hamper the cutting ability.
However there is a bit of an issue with the guard as for a lot of paring work a grip similar to the classic reverse grip is used and the guard does make this awkward and a knife which is easier to grip up around the handle is more functional. However on this knife that guard is integral as it is the actual flipper and this also serves as an index finger choil/guard.
Moving beyond shallow cutting, the influence of the :
becomes evident even doing light work such as slicing a carrot. While the flipper can slice carrots without breaking them, compared to a decent kitchen knife it does require significantly more force :
The difference is small, just a couple of pounds but percentage wise it is large, ~50% which is why of course kitchen knives for dicing carrots are not ~5/32" thick and approximately an inch wide.
Of course not everything to be eaten are vegetables, on meat work the main requirements for high performance are :
The flipper works well for short term work however for serious use the cutting ability isn't the issue just the fact that the knife will come in contact with heavy grease/fat and it isn't trivial to clean it compared to a simple fixed blade. But the general shape of the blade is a solid working pattern and the handle is perfectly safe/secure in hand.
Of course for cutting cooked and rendered thick pork skin, the simplest way to cut it is a straight rocking push and a short blade like the slipper is required to make multiple cuts.
Ergonomics : the handle comfort is high as :
There are a couple of sharp peaks on the from of grip however a little bit of time on some sandpaper took care of that easily.
The only real downside of the grip is that since it is all metal it will become uncomfortable in lower temperatures faster than G10 or Micarta. But in general aside from that, it is a well designed handle, very versatile in a broad range of grips.
Security : the security of the handle is a strong point due to :
Even in very dynamic cutting there is little concern for the hand sliding up on the blade.
Durability : the handle is solid Titanium, it is extremely resistant to temperature, weathering, chemical attack and even impacts and abrasion. The most that is likely to happen is that it will get a bit scratched up and due to the finish even that is going to have a very small impact.
Clip : the clip is one of the strong points of the knife as it is very comfortable in hand while having strong retention. The comfort is achieved though the very extensive rounding of the clip plus the fact that the tip is dropped under the main body of the slip which prevents it from being a high pressure point.
The lock/action is one of the weak points of the knife. In general liner and integral locks are very sensitive to the geometry of the mating faces and if they are not perfect then the locks can be :
This knife does not have the first problem which is the most serious, however it will over engage in heavy use and become very difficult to open as it will almost jam. Now to be frank, many long term integral lock makers/manufacturers have this problem, it is common with Sebenza's for example. However with proper construction (R. J. Martin, Elliot Williamson) the locks can be both very smooth and very secure.
This one flips fairly easily but isn't as smooth as the knives can get which will actually just fall open once the detent is passed. The detent is however very well done as it keeps the blade very secure, it can not be shaken open but is not so much of a stop that it prevents easy flipping.
As with many integral locks, the knife is not that easy to open/close with gloves, especially larger winter gloves.
S35VN was a response by Crucible to improve on the toughness and ease of machining/grinding S30V.
S30V
S35VN
The main change was the removal of 1% Vanadium and addition of 0.5% Niobium. Niobium tends to form its own MC type carbides where Vanadium forms both MC carbides and dissolves in Chromium carbides. The use of Niobium to partially substitute for Vanadium thus increases the wear resistance and corrosion resistance. However as there was a 0.5% hard carbide loss then S35VN would be expected to have a slightly lower abrasive wear resistance.
According to Crucibles data sheet has a 15-20% increase in toughness over S30V which would be expected given the slightly lower carbide volume (and carbon content). According to CATRA testing by Bohler is about 15% behind in low sharpness edge retention slicing abrasive paper (CATRA, silica) 1 which would be expected for the same reasons.
As for edge retention, slicing cardboard, it performs as expected, similar to other high carbide stainless steels 1 Interestingly enough, the initial uses of the knife tended to produce an edge which rolled and chipped, one of the main complaints about the steel when it first came out. However cutting random materials tends to produce random effects on the edge and in general the behavior of the steel was similar to S30V in extended use.
As a point of comparison, in trials compared to a knife in SPGS (near left) compared to the S35VN image (far right). In general the SPGS tended to take less damage due to :
However while observations like that tend to match the properties expected from the materials data it has to be kept in mind that these differences are very small and in order to see them then multiple trials have to be ran, the average results need to be considered and the geometries of the knives have to be near identical. If any of these are not the case then their influence could be seen vs the properties of the steel itself.
Sharpening, was very similar to S30V. In order to grind it efficiently then sharpening stones need to be used which can cut high carbide steels, traditional / natural stones tend to be problematic. This isn't to say it can't be sharpened on an Arkansas stone, the stone is quartz which is harder than the steel, just that the very hard vanadium/niobium carbides are significantly harder than quartz and other similar natural abrasives and thus the cutting action will be significantly reduced.
The edge was normally maintained on a MXF DMT plate to keep it at a fairly high polish (6 micron). A micro-bevel with a 25 micron diamond rod was used when a more coarse edge was required for edge retention slicing abrasive materials. Significant grinding to remove material, adjust the edge angle and thin the blade grind was normally done with a Naniwa Superstone 400, Bester 700 or SPS-II 240 depending on how much material had to be removed.
A few changes/alterations :
Overview :
Comments can be emailed to Please Use the Forum or by posting to the following thread :
and/or the YouTube Playlist for Gavko.
Most of the pictures in the above are in the PhotoBucket album.
1 : Edge retention slicing carboard, various steels
2 : Bohler Catra
| Last updated : | |
| Originally written: | 31/10/2013 |