M2 Sharpenability
- I thought I'd have to say a few words in defense of M2 here :) Very often people curse at M2, complaining that it's too hard to sharpen. First of all, everything is relative :) Depends what do you compare it to. I've mentioned above that M2 is harder to grind than ATS-34/154CM used by the same Benchmade. However the difference is not anything dramatic. You'll notice it, but it is not the magnitude order. Obviously grinding M2 is much worse than 440A or 425M used by many manufacturers. However everything has its price and there's no free lunch either. Simply put, increased difficulty in grinding means that during cutting, the edge will loose metal with greater difficulty as well, keeping your knife sharp 5-10 times longer than low end alloys. Of course it's not that simple, edge holding depends on many factors, but this is one of the most important.Is it worth it? Up to you to decide what do you want. Ease of sharpening plus frequent sharpening of the other way around. To me, M2, (and BG-42 and some other "hard to grind" steels) are definitely worth extra effort in grinding. The benefits definitely outweigh sharpening probs :). Once again, M2 is not any more difficult to grind than BG-42, D2 or the same ATS-34 heat treated by Paul Boss. I'm talking only about the steels I have experience with.
As always, the most depends on your skills and tools being used. If you don't know how to sharpen your knives properly, or If you try to reprofile M2 blade with a relatively high grit hone, obviously you'll be disappointed. People out there try to resharpen M2 blade with Spyderco sharpmaker, or Norton fine stones. Sure, they can't get the job done for hours and then blame M2. But those are not the right sharpening tools for serious sharpening and bevel reprofilng. Try DMT, Edge-Pro, etc, and you'll find it is not that hard. Sharpmaker and other fine stones are good closer to the end, once you get the primary bevel done, to get the fine, razor sharp edge, or for touchups, but not for profiling.
Blade
- The blade in both cases with M2 & ATS-34/154CM, was shaving sharp right out of the box, however too thick and really rough. I'd expect a better sharpening job for a 100$+ knife. I like the geometry of this blade a lot, it's good for slicing, cutting, stabbing. The blade has a lot of belly and a recurve for improved cutting/slicing ability and the strong point for stabbing. I already said quite a bit about M2 steel, but those who prefer stainless steel blades, there you go, ATS-34/154CM allegedly the one of the best stainless steel available for knife blades, by now (2001) Benchmade has already switched to 154CM by Crucible as their blade material, which is practically identical to ATS-34, except that many knifemakers claim that it's a finer grained and cleaner steel and made in America, not in Japan.For the record, the edges on both 710-s and many other BM knives I've had were far from perfection. This is nothing new with Benchmade and practically every other factory knives. Their sharpening job definitely could've been better. Basically it can be broken down to 2 things, coarse edge, and the edge thickness. Yes it was sharp, but on both blades the edge grind was uneven, I could clearly see the machinery marks. It was far from what can be described as mirror polished or micro serrated :( Matter of fact, it was rather coarse. Those who know how to sharpen the knives would not care too much about that. I sharpen all of my knives to my personal taste and requirements. Still I think Benchmade could have done better work, for example every Cold Steel knife that I ever had, has much better finish. Not that it'd make AUS-8A outperform M2, just sort of frustrating, why that is such a problem to put a normal edge the knives.
Another issue with the blade is the angle it is sharpened to. Too high for a folding knife, more than 50 degrees included. Better to resharpen it to the lower, 18-20(36-40 degrees included). Kindda hard to perform this operation on the M2 blade without proper equipment, but it will pay off :) There was a very good thread on BladeForums.com addressing Axis 710 edge resharpening, where Joe Talmadge provided very detailed information how to make your Axis perform better. Click here to read.
To be fair, the edge thickness is not something specific to Benchmade. Most factory knives have the same problem to some extent, partly because of the customers too. For those who don't take care of their knives, and don't know how to sharpen them, thicker edge translates to increased edge holding ability and is harder to dent, roll, etc. The bottom line to me is that there is no excuse for poor NIB sharpening job, but it's hardly the greatest concern of mine :)
BT-2 Coating
- Benchmade proprietary BT-2 Teflon coating looks very nice (for those happy times before you start using the blade) & as the manufacturer claims it exceeds by 4000% the standard corrosion resistance requirement for stainless steel knives, also Teflon as one of the most slippery substances, thus the coating should add some to the knife's cutting ability. Having 2 Nimravi, stripped and BT2 coated, I have to say I can't tell any advantage of the BT2 in terms of cutting. Sometimes I feel that non coated blade would've been better to clean, especially when it is polished. Anyways, the coating tends to wear off & very easy to scratch. As of this moment Benchmade doesn't offer refinishing, but they may provide this option in the future. However this is less likely with the introduction of the new coatings and the demand for the BT2 refurbishing doesn't seem to be all that overwhelming :) Rather the opposite, folks are asking to forget about it. You can check Benchmade FAQ for more info. Other than that, all I can say is that after first use BT2 will look like hell :) Theoretically Teflon penetrates the pores in metal, thus still protecting the blade even when worn from the surface. Beat up look is fine with me on the worker knife, but in general I'd really love to have more durable coating. Click here to see my trusty 710 after 1.5 years of use. Actually the coating looks worse than on the pic, just the net of small scratches doesn't show on the pic well, but more or less you get the idea.Boron Carbide coating
- In 2001 Benchmade included a new coating in their assortment - Boron Carbide(BC) by BodyCote, for the reference BodyCote also offers additional Hard Chrome(HC) layer under BC to improve corrosion resistance. The first blade to receive the new coating in BM lineup was Osborne 770. Overall everyone's very positive about Boron Carbide. Here's a link to the reference thread on the bladeforums. Ideally we'd get 710 and AXIS AFCK with BC coating instead of BT2 :)I've decided that it would've taken too long to just sit and wait for the ideals, and did it myself. Speaking precisely, I've sent my 710 blade along with the other 2 (Ares HSSR and one more Nimravus, mirror polished) to BodyCote. Got them back in couple weeks, for the curious minds - here's the picture. 710 has BC+HC over bead blast finish, 770 that had it's blade replaced by BM has BC over satin finish, and finally Ares and Nimravus have BC+HC over mirror polished finish. You can see the difference in appearance. Overall BC over bead blast is darker, non reflective, but harder to clean. As of durability, I don't have much data yet, but will post it here as soon as I have something. For more info on BodyCote and BC coating check Nimravus review and the Knife Modifications section.