Hallo all.
I just got a Haco, and even if all is conforming in this piece, the very strange thing is the...turned handle.
I have opened the dagger, and really handle and guards seemed very 'frosted' with the tang: I'm sure it has been never dismounted in the last 60 years and consequently this is not a part dagger.
But the handle is without any doubt "turned", "bended" on its axis (hope you understand what I mean): seems it has been stocked somewhere in someway with a lot of weight crushing on it....have you any other ideas ????

That is not unusual. As the grip dries out with age it sometimes will twist. I had a really nice Undine that had a greater twist than yours. If you look at a lot of these daggers you will see that many have a slight twist. You don't notice it until you view it from the top down.

Essentially a quality control issue, Skyline sums it up nicely being something that is not uncommon with natural products as compared to man made. When wood shrinks it does not shrink in just one direction, but in multiple ways with some parts of the grain being affected more than others.

Woodworkers use a term called “seasoning” where the wood is dried over a long period of time to stabilize it by removing excess moisture. The necessity to stabilize wood first before working it was a very well factor to be taken into account. For example, rifle stocks adhering to German Army Heereswaffenamt standards called for a maximum of 12% moisture content along with some other criteria.

Overall I think it’s fair to say that some dagger makers did a better job making them than some of their compatriots. My personal sense of it being that those who also had military contracts oftentimes having fewer quality control issues. FP

Thank you all, just learned something new: never I'd thought it was only a problem of...umidity.

I previously owned an Eickhorn with the same "twist". However, I speculate a slightly different explanation. I believe that in addition to the natural drying of the wood in the handle, the torque from the top nut creats an upper right pressure on the top crossguard that is transferred to the top part of the grip. The dagger I owned that had this appeared to have never been taken apart and the torque twist was in the expected direction as my armchair explanation details. I welcome your thoughts on this.

Wood is hygroscopic and can acquire moisture from the atmosphere, but it also will lose it the same way. And over a long period of time the net loss of moisture under average conditions will exceed any temporary gain(s). As I understand the underlying idea - it is that pressure from the pommel nut downward forces the crossguard into the wood causing the grip to twist sideways.

There are a number of ways to look at the problem. And possibly even additional contributing factors. Such as the uneven nature of the interior of sand cast crossguards. And/or counter arguments - such as the fact that the downward pressure is on the end grain. Which arguably is the least affected by pressure, as compared to other forces which might cause twisting with wood grain that is linear. But I like a simpler more direct approach.

It has been argued (especially IMO by those who are selling or possibly trying to validate a particular item) that most noticeably with the many broken SS grips (at the grip/crossguard edges) it is all due to wood shrinking. Not the fact that somebody was fooling around - and may have tried to force a better fit in mating parts that might not have left the factory together.

When wood shrinks its volume diminishes. It does not get larger. Meaning that it pulls away from the wood instead of expanding into it. And if it pulls away from the metal parts it will exert less force not greater force. Versus wood that might not have been fully seasoned (and assuming there is no evidence of water damage). FP

Typo correction. Make that: "Meaning that it pulls away from the metal instead of expanding into it". FP