Benchmade 805 TSEK M390 Steel LE
Axis Lock Folding Knife Review

During the knife collecting years, I did have a few versions of the Benchmade 8xx series knives at one time or another. You can check out Benchmade 800 AFCK review and Benchmade 806 AFCK D2 Folder review. To be precise, Benchmade TSEK-s were out there for a while already, and I wasn't really interested in them, originally they had liner locks, and later when they appeared with axis locks, I kindda overlooked it, because I already had the other two and, neither Gin-1 steel nor 440C steel weren't really what I would be interested in.

However, in 2010 special edition of the 085 TSEK was announced in Bohler-Uddeholm M390 steel, exclusive to knifeworks, and I finally decided to get one. Mainly based on positive feedback form other knife testers regarding M390 steel. I've placed an order and then the usual waiting game started. Not much of a game though. TSEK series was already discontinued by Benchmade, and this run was a limited edition, which came to be only because of persistence of knifeworks. Still, things take time, and you just sit and wait for your new pointy toy, not much fun when you think about it. Anyway, waiting has an end and in January 2011 I've receive the knife, #120 of 400. In other words, there were just 400 of them made, and I managed to snatch one :) And in an exotic steel like Bohler-Uddeholm's M390, well about that further down in the review.

General

The blade has nice satin finish, no blemishes and scratches. Bevel was evenly ground, even if not too polished. The action was butter smooth right out of the box, and there was zero blade play. More often than not, even high end factory folding knives do require some sort of adjustment and/or lubrication to achieve this level of smooth operation and zero blade play. Carbon fiber handle is also very well made, precisely fit, there are no protruding or poking parts and the texture is very nice, smooth yet secure enough, not to be a problem. There's no solid backspacer on the knife, but there are two anodized barrel backspacers and plus one more pin in the front, and plus the axis lock bar itself also acts as a support for the handle. Overall, the handle feels very solid and sturdy, and so does the whole knife. Completing the description, let's mention the nicely polished clip which is fully reversible, left/right, tip up or down. So, in short, it is quite a knife, even for its price.

Update 10/11/2011 - I was really baffled to find out that after about a week of carrying in October, the blade went off center, severely off center at that. It is touching the right liner. To make things more complicated, my attempts to adjust the blade centering via pivot screw were utterly fruitless. I've carried the TSEK 805 M390 before, few days here and there, and last week decided to switch from Spyderco Endura 4 ZDP-189 folder to TSEK. Carried a week and then this happened. Blade getting off center so severely is not something I would miss on the folder that I carry. I didn't notice any symptoms during earlier carrying sessions, so this must have happened during last week. Very strange, developing that much of a shift in a week. Called Benchmade support, that guy was very friendly, I asked if there was something I could to on my end, to avoid the shipping back and forth ordeal, but he said, if it's that far gone, I wouldn't be able to do anything. Sent the knife next day.

Update 11/02/2011 - The knife came back on November 2nd. Repairs were completed on October 31st. Pretty good turnaround time, all things considered. The problem was fixed. The blade is almost perfectly centered, and the action is still very smooth. One thing I am not too happy about, Benchmade warranty service sharpened the blade and I really wonder why. Ok, I understand, they were trying to be nice, and threw in free sharpening, but damn it, the knife had 15° per side, 100K mirror polished edge, which was a lot sharpen then what it came back with - ~20° per side, barely 800 grit finish. Thanks for trying to be nice, but come on, no way you can miss that kind of edge, so why make it worse, and I never asked for sharpening... Well, there's a lesson for you, if you do not want sharpening, explicitly request in the warranty form - DO NOT SHARPEN PLEASE! In short, I have to sharpen it again... Probably I won't go 100K again, I want to experiment with relatively rough edges. So, I figure I'll go about 3K and then strop on diamond crystal loaded strops.

Blade

The original edge on the knife was about 18°-20° per side. Officially the blade is hardened to 60-61HRC, just 1 HRC shy of its maximum theoretical hardness, specified by Bohler-Uddeholm, which for the record lists 58-62HRC as the acceptable working hardness. Given all that, I assumed, or hoped blade would be at least 60HRC. So, I figured lowering the edge angle to 14°-15° would be a good start. I've proceeded with sharpening, which wasn't very difficult, since the original edge was pretty good to begin with.

Started with 1200 grit King Super whetstone, and followed with 2000-3000 grit Synthetic Blue Aoto stone. Each step took less than 5 minutes to achieve smooth scratch pattern and raise the burr on both sides. Next was the Naniwa 5000 Grit whetstone, and 10000 grit Naniwa Super Finishing whetstone. Final steps as usual were stropping on 0.50µm and 0.25µm diamond loaded leather strops with 0.30µm aluminum oxide abrasive film, and stropping on a leather strop. Now the edge was what I wanted it to be, especially on the knife of that class. Initially I was unsure which type of the edge would work better, coarse or high polished one, after all it was my first knife in M390 steel, but initial results were pretty good, I mean high polished edge. Later, during next 4 years of use I had more than enough opportunities to use it with coarse edges around 1000 grit and high polished edges. Out of many high carbide volume/high wear resistance alloys, M390 is one of the very few that can perform well with fine, high polished edges, although with ~800 grit edge it is a very aggressive cutter.

M390 Steel

Today, Bohler-Uddeholm site lists M390 as a knife steel. However, that wasn't always the case. Originally, M390 steel was designed for plastic moulds, and if you do a little digging, that's easy to find out. I'm not trying to say M390 is a bad steel or sub par by any means, just like many other very good knife steels, it just happens to work well for knives, and that's it. Plastic mould knives require high wear resistance, and since they're used in highly corrosive environments, high stain resistance is also a desired property. Hence 20% of Chromium in the alloy and 4% Vanadium, along with 1.90% Carbon.
M390 isn't the only alloy in the family. There are several alloys from different steel makers, with virtually identical composition. Latrobe Duratech 20CV steel was used by SOG, Carpenter CTS20-4p steel used by Spyderco. The differences in compositions are negligible. As you can see, in one version or another, quite a few knife companies are using this alloy. Except, M390 got most of the rave. Apparently, part of it can be attributed to Benchmade marketing too.

Handle

Overall, the handle shape and size is very much like 800 series, long, gently curved, with a finger groove. There's a lanyard hole at the end, although it's very close to the clip as it is installed out of the box. I don't think it'll get in a way though, but for the thicker lanyards it might be a problem, the edge of the clip can cause excessive wear. That's just my guess though, I pretty much never use them lanyards anyway. Have one on Scott Cook's Locsha, because it was there when it arrived, almost gone by now :) In the end, I really like the handle as it is.

Usage

There was also a rubber foam block left over from earlier remodeling. Just like cheese, that thing loves to stick to the blade, and it isn't edge friendly cutting material at all, although quite manageable after all. The main problem with it is the lateral loads on the edge, which becomes unavoidable, due to the fact that it's sticky and flexible. Can't avoid it. The result was the most considerable edge degradation in all the testing. I figure, the fact that I did the rubber block cutting at the end didn't help at all, but I doubt very much that had I done the same rubber cutting at the beginning, the result would've been very different. At any rate, that sort of cutting is very harsh on any edge, and wires are used for a good reason.

As far as the cutting ability goes, with the highly polished convex edge around 15° per side and sabre grind, it was really high. The knife simply glided through everything, ok everything except the damn rubber. I didn't bother with prying, even though for some reason, quite a few knife testers and users feel the need to do so. It's a folding knife, not Busse FFFBM Battle Mistress.
Handle on 800 series is a little on the bigger side, at least to my taste, but gotta give credit where it's due, it is very comfortable in any grip and after those 4 hours of works, I didn't get any sore spots or irritation on my palms. Carbon fiber scales just make things even better. Overall, its usability and ergonomics are very good, action is very smooth, axis lock is easy to operate and one of the best folder locks out there. So, if the price isn't the problem, then the knife is definitely worth getting. For the EDC knife, it's a really nifty piece, if the blade of that size is ok in your area to carry.