For Cliff Stamp

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sophijo

Joined
Mar 10, 2003
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Cliff,
I'd appreciated your learned and esteemed opinion on Fallknivens laminate blades.
Thanks,
Dave
 
Laminated blades are *VERY* popular in Japan. The outside core is usually a very easy to machine material, mild steel or even wrought iron. Iron made the blades very cheap, because you didn't need to use expensive steel for anything but the edge. The reasoning being what use is there for that since you only cut with the edge.

There were also lots of other benefits such as when sharpening, only a hint of material is hard to remove. The rest of it is dead easy. The edge then sharpens very quickly, even when you have to remove a small nick (try this out on a non laminated chisel, the difference is massive). As a further aside, when the tools are heavily abused they don't tend to crack, but just bend, which is much easier repaired.

The only downside to laminates is that they make the blade *MUCH* weaker. Now it can bend all over creation, however if you look at how much force it takes to induce a permanent set, this is much lower with the laminated blades. This isn't a concern with the Japanese blades (and saws) as they don't pry with them. Any significant prying is considered very abusive, and generally indicates someone who doesn't know what they are doing.

When I first used a few Japanese saws, I bent them readily, being used to western saws. With more practice, I had no such problems with the saws. Now you could ask, why not spring temper the blade - well the reason is that you don't need to with proper technique, and if your technique is off, then so is your carpentry and fix this instead of wanting a tool that allows sloppy work.

I have used laminated puukkos and forged carbon steel ones. Much of the above applies. However when using the knife as a general tool, the laminate is vastly more restricted in use because it bends far easier than the through hardened carbon steel one. Now if you are just cutting then this doesn't matter, however if you are doing more utility work it can be important.

So as for the Fallkniven blades, if they were made for just cutting, being highly optomized precision tools, then an arguement could be made. However look at the designs, some of them like the A1 for example are clearly intended to take heavy loads, both on the edge as well as through the main blade body. When this starts to be a factor, the lower strength of the laminates is a factor.

Now Fallkniven promotes the laminates as being stronger, and they are if you look at the ultimate tensile strength. This is the point at which the knife snaps, however if you look at the yield point, which is where the knife takes a set, they are likely weaker. I asked Fallkniven for specifics on this issue with no reply.

So there are lots of positives, the new laminates will take more impact than the old ones, as AISI 420 should be tougher in this regard, it is also far more corrosion resistant, so you get much better resistance to pitting along the primary grind and flats. It is also likely to be harder to completely destroy because of the greater extent of bending.

What you don't get it any more edge toughness as it is still VG-10. In fact the edge might be significantly weaker depending on how much of it is AISI-420 (use a 420 knife and see how easy the edge dents). The blade body as a whole is also not going to be as stiff and thus will flex easier, making it a less effective prybar in some respects.

What would be informative is testing by Fallkniven in the areas of where the change weakened the design, not just where it improved it. The tradeoffs are always of critical interent. However to be fair, this is rare in the industry as a whole.

-Cliff
 
Cliff,
If you lived down the road I'd bring you a crabapple pie and a couple venison pasties(meat and veggie pie)! Thanks for the thorough reply. I appreciate the effort you make and the time you spend answering these questions on the forum. I always study them intently.
Thanks,
Dave
 
Thanks for your report Cliff it is as usual complete and competent.

Laminated blades are very popular in Scandinavia also. Helle, Brusletto, knives from Mora. I have two Helle knives and a lot of blades. I do not experience any blade bending with this blades (However I bended tip of my first Hiro LB - but it is from Japan). I notice that tang is easy to bend when you put it into the handle, but blades does not have any problems with bending. And blade thicknes is about 2.5mm 3mm. Not much then Spyderco Native has.

I have Fjellkniven, Brakar and Safary blades for selfmade knives. They are strong, sharp ett - as you sad, but they are not intent to bend.

As I understand Helle has blades from Norvrgian steel institute and I read a rumor that powder metallurgy involved (same as Damasteel). May be this is a reason why norvegian blades are different?

Thanks, Vassili.
 
When I was a teen I bought a Norwegian laminated blade knife because they advertised a miraculous ability to be bent 90-degrees without breaking. When I got the knife I was quite disappointed that the blade was rather easily bent and had less spring to the blade than any knife I had ever seen. I had expected the blade to spring back from 90-degrees and it wouldn't spring back from 5-degrees. I have similar laminated blades now that are no problem since I never bend knives anymore.

On the other hand the Fallkniven blades are generally much thicker than other laminated blades that I have seen. An A1 or S1 may be sufficiently thick that bending will not be a common problem. I just wouldn't get one if I intended to do any prying. The fully tapered blade on the F1 may be an issue. The grind on most scandinavian laminated blades is a variant of a sabre grind and provides more lateral support for the edge. The F1 might be vulnerabe edge rippling under high stress cutting.
 
Vassili, the stiffness is strongly dependent on how thick is the core, and how hard is the side laminate. How important this strength is depends on what is being done with the knife. As Jeff noted, it is not an issue with cutting with skilled technique, which is why it is completely ignored in Japanese blades.

However the Fallkniven knives are not so restricted in use, especially the larger ones. These are meant to be chopped with, beat on and with, used to split wood, dig with the tip, and for heavy prying. If this isn't the case then the basic design is incoherent, as that is the only reason you go with grinds that thick.

When the user starts getting very heavy like that, strength starts to become very criticial, both in keeping the blade and tip from getting bent, as well as the edge from rippling.

-Cliff
 
OK. I am talking about Helle Fjellkniven (not Fallkniven A1 or NL) and Safary. I just check the blades: they have flat grind and line between layers is a bit visible and is about 2/3 from the edge - so then core is 4 times thicker then one side. It is twice more hard steel then 18-8 (coockware steel Helle use for sides).
Hiro LB from other hand has 2/3 core of one side layer - core layer thiner then one side, but it is VG10 on the core and on the sides too.
If someone has Fallkniven please check how actually thick the core is.
Thanks, Vassili.
 
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