BM Mini Dejavoo

Razor

Razor

Gold Member
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Dec 8, 1999
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I really like how this knife feels in the hand. Kinda thinking about getting the large version. Are these knives made for heavy use, EDC, hiking, hunting?
 
man I like the mini dejavoo so much i'm willing to carry it in my right pocket and open with my right hand despite being a lefty! I wish they would have made it ambidextrous opening but I guess that is what the onslaught axis series is for (although it's a very different blade).. it's a shame though because it is one of my favorites.
 
Razor said:
I really like how this knife feels in the hand. Kinda thinking about getting the large version. Are these knives made for heavy use, EDC, hiking, hunting?
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No the dejavoo is made for light edc and it excels at that imo. The relatively weak liner lock and smooth sculpted g10 scales make it unsuited for heavy use. The 745 is one of my favorite knife designs.
 
I love the design, and believe me, I'm not normally one that's critical of lock strength, but the liner lock on this one felt like I can snap it in half between two fingers. It's the first "nice" knife in...well, 5 or so years that I turned down because of lock strength.
 
I just got one of the large Dejavoo's on closeout and I don't know why I waited so long to get one.

The small model is nice , but as you can see in my pic, the large Dejavoo is not all that big.

As far as hard use , I'm not so sure I'd say this knife is week. The Ti liner is about as thick as my BM Stryker and locks up very solid, but the frame does have some holes to lighten it. It opens very easily because of the weight and length of the blade.

I can't say enough good things about the knife.

DSC01003.jpg
 
kawr said:
No the dejavoo is made for light edc and it excels at that imo. The relatively weak liner lock and smooth sculpted g10 scales make it unsuited for heavy use. The 745 is one of my favorite knife designs.
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Artfully Martial said:
I love the design, and believe me, I'm not normally one that's critical of lock strength, but the liner lock on this one felt like I can snap it in half between two fingers. It's the first "nice" knife in...well, 5 or so years that I turned down because of lock strength.
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I gotta disagree here - I'm more confident in the 745's titanium liner-lock strength than that of the other liner-lock knives I've owned (which, btw, doesn't include striders, the hest/f, or other titanium frame-locks). Plenty of titanium to resist snapping "between two fingers" :p.
I made use of Bluntruth4u's modification to enhance closed-retention and also push the liner further when open. I trust that lock over my axis-folders. Nothing weak about it.

That said, what exactly do you intend as "heavy use"? I use mine for edc, hunting, hiking, carving wood, food prep - no issues, and it's still sharp. It's no fixed-blade, but with G10-scales, S30V blade, titanium-lock, steel other liner, ergonomic Lum-design... definitely a favorite. But that's the 745.
I've no experience with the larger 740... owners think the 740 liner is weak??:confused:
 
chiral.grolim said:
I gotta disagree here - I'm more confident in the 745's titanium liner-lock strength than that of the other liner-lock knives I've owned (which, btw, doesn't include striders, the hest/f, or other titanium frame-locks). Plenty of titanium to resist snapping "between two fingers" :p.
I made use of Bluntruth4u's modification to enhance closed-retention and also push the liner further when open. I trust that lock over my axis-folders. Nothing weak about it.

That said, what exactly do you intend as "heavy use"? I use mine for edc, hunting, hiking, carving wood, food prep - no issues, and it's still sharp. It's no fixed-blade, but with G10-scales, S30V blade, titanium-lock, steel other liner, ergonomic Lum-design... definitely a favorite. But that's the 745.
I've no experience with the larger 740... owners think the 740 liner is weak??:confused:
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The reason I say the liner is weak is not because of the thickness but how it lacks springyness. There's literally zero tension in the liner lock and I can unlock it just by squeezing my hand when gripping the handle. I've owned 3 different 745s and they all were like this including the one I currently own. Like I said its a great light edc but there's no way I would do any sort of heavy work with it.
 
kawr said:
The reason I say the liner is weak is not because of the thickness but how it lacks springyness. There's literally zero tension in the liner lock and I can unlock it just by squeezing my hand when gripping the handle. I've owned 3 different 745s and they all were like this including the one I currently own...
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Ah, I hear you - fixed that with Bluntruth4u's mod, mentioned in my previous post - wedged a tiny bit of folded paper behind the liner. I used less than he suggests in the vid, and not only will the knife not open on it's own (while still easy to flip open), but now the liner snaps in places tight. I highly recommend the modification - I wouldn't praise the knife, wouldn't allow friends and family to use it, without this adaption; but now I trust it second only to my fixed blades. Try it out. Just adjust the paper (via folding, etc) to your preferred liner-performance level before cutting the paper-tail off. :thumbup:
 
by volume, titanium is substantially weaker than steel. Being titanium, in this instance, actually makes it weaker.
 
Artfully Martial said:
by volume, titanium is substantially weaker than steel. Being titanium, in this instance, actually makes it weaker.
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Weaker how? I don't know how easy it is to snap a steel liner in half vs. titanium, but my understanding was that titanium has higher tensile strength... is that also by mass rather than volume? You may know much more than I about this. I theorize that the steel liner will fail sooner due to fragility vs titanium, i.e. it requires more force to bend but will permanently deform or snap (fail) under stress which the less dense titanium will endure... ?

But what level of stress (e.g. spine-'whack') do you think would be required to "break" the lock on this knife (vs. if steel had been used), and do you think it would fail before the pivot, stop-pin, or screws?

I'm really curious as I'd never thought about comparing steel to titanium liners/lock performance before... The weight difference between the two seems negligible. Do you think any real advantage is gained in regards to corrosion-resistance in this particular application? (obviously this isn't a dive-knife)
 
The larger version imo is the better knife.

I bought the larger version first, then the smaller. The finish on the smaller version blade was NOT as good as the larger. The finish on the larger model was like a mirror....real smooth...beautiful. The finish on the smaller one had a stonewashed look, and was waaay noticeably different looking side by side. Maybe i got a lemon as far as blade look on the mini??

No matter which one you get, they're both awesome. I'm not a big user, but i know they could handle light to moderate edc use.
 
no, it's substantially weaker by volume than steel. Like, half as strong by volume. And yes, it's much, much softer too.

The strength of titanium, by mass, is excellent. An equivalent weight of titanium will easily be more rigid than that weight in steel. But we're discussing thickness, hence volume, and in that sense, stainless steel will substantially outperform titanium.

Here's a quick citation. I only read this article briefly for the purposes of supporting this, but it should explain things better than I can.

http://swordforum.com/metallurgy/titanium.html

titanium-size.jpg


So titanium is definitely the metal of choice for projects requiring low weight and where hardness is not important. Where volume is the relevant factor, or when weight is considered irrelevant, steel will outperform it quite handily.
 
Artfully Martial said:
no, it's substantially weaker by volume than steel. Like, half as strong by volume. And yes, it's much, much softer too.
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Hardness depends on heat-treatment for both 420J Stainless Steel and 6AL 4V-TITANIUM. They could be the same hardness...

Artfully Martial said:
... But we're discussing thickness, hence volume, and in that sense, stainless steel will substantially outperform titanium.
Click to expand...

What we are talking about is stress, measured as "ultimate tensile strength" in force per unit area (not mass/weight/density), and according to Wikipedia here, unless I am reading this wrong (again, not something I know a lot about), the titanium alloy used in this liner is indeed stronger than the steel one and is also only half the weight!

(if it weren't would Benchmade or anyone else bother using it, given cost of production??)
 
But 420 isn't a blade steel, it should be used for liners etc. Yes, I know that a lot of companies haven't picked up on that yet...but in the companies we're looking at, that's the only place you'll see 420 used.

You're right that, by weight, titanium is far stronger. But per cubic centimeter (or whatever measurement you like), it will actually be substantially weaker.

So in regards to lockbar thickness, a thin strip of steel will be, roughly speaking, about as stronger as a titanium alloy less than twice its thickness.

But more to the issue of the Dejavoo itself, I'm not sure why the examples I played with felt so flimsy--it might be due to the linerlock, or the pivot, or general fit and finish. It might be that I played with three unusually weak ones in a row, but I do consider that improbable.

Don't get me wrong though, I actually really love the design of the knife--and I am absolutely NOT one of those guys that goes on and on about how a lock should be able to hold the weight of a whale or something...lock strength is pretty low on my priority list. Still, I just had a real feeling of doubt when holding the Dejavoos.
 
Well, who knows, perhaps I'm wrong, but I've read that for years. I'm by no means a metallurgist. Hopefully someone more knowledgeable than I will speak authoritatively on it.
 
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