HTM Gunhammer in M390, a Darrel Ralph design
By crimsonfalcon07
September 2012
Table of Contents
Specifications and Pricing
History and Details
Unboxing
The Blade—Grind, Geometry, and Performance
The Handle—Ergonomics and Design
The Lock
Fit and Finish
Odds and Ends
Pros and Cons
Conclusion
Specifications and Pricing
The HTM Gunhammer in M390 is a Knife Center exclusive limited edition. I received mine as a prize for winning a photo contest put on by the HTM crew on Blade Forums in the
HTM Subforum. There are only 30 pieces of each run, so you will need to look for them on the secondary market, as the plain edge variation is no longer available at the time of this review at Knife Center, although the combo edge is still listed as being in stock. The knife is 4.25” long closed, and 8” long open, with a 3.5” blade, making it legal for carry in most states in the U.S.A., although you may want to check your specific laws. I will not be held responsible if you are not aware of the laws in your area.
The blade is made from Bohler M390 stainless steel, which is currently considered a “super steel” by some, due to its fine performance. The blade is tempered to 62 HRC, and comes in either a satin finish, or a non-glare finish using HTM's excellent DLC (diamond-like-carbon) coating. Mine is the satin finish. The knife uses Darrel's bowie shape, and comes in either combo or plain edge. This particular knife is the plain edge variation.
The handle is made out of 3D-machined aluminum, which has been anodized in a black Military Type III hard coat. The texturing on the handle is Darrel's ETAC (ergonomic tactical) design, which provides a solid grip and an elegant look. It weighs in at 5.2 oz (compare to 4.7 oz for a large Sebenza, or 5.8 oz for a ZT 0560), and uses a hefty .09” Titanium liner lock to secure the blade in the cutting position. The knife uses Darrel's Assisted Opening mechanism, which has more kick to it than any other AO mechanism I've ever used. More on that later... Some of you may be happy to learn that it is Made In the USA (capitalized on purpose). The knife retails for 234.95 USD for the combo edge which is still in stock.
Specifications
Blade Steel: Bohler M390 Stainless Steel, 62HRC
Handle Material: 3D Machined ergonomic ETAC GRIP
Blade Style: Bowie, Plain Edge or Combo Edge
Blade Finish: Satin, Non-Glare
Blade Length: 3-1/2"
Open length: 8"
Closed Length: 4.25"
Locking Mechanism: 0.09” Titanium Liner Lock
Weight: 5.2 oz.*
Made in the USA
Lifetime Warranty
History and Details
The Gunhammer was introduced in 2004, and has become one of Darrel's best selling designs over the past 8 years. During this time period, it has seen a number of changes, from new pivots, different thicknesses for the blades, changing grind heights, to new anodization techniques. Darrel and HTM (Hand Tech Made) are constantly looking for ways to improve their product. Darrel has been described as a visionary, and as a custom knifemaker whose work is so in demand that it has been described as “some of the most sought-after in history.” I admit to some bias, in that Darrel has been my favorite designer since I got into knives. I believe the Gunhammer is so-called because the styling of the flipper is reminiscent of the hammer on a Colt Commander pistol.
A fair review should note that HTM's QC team experienced a number of issues during the release of this knife, and was subsequently let go by HTM. Some customers did receive M390 Gunhammers that were not satisfactory, so if you do end up with a defective model, please do call HTM at (740) 965 – 9970, and I'm sure they will take care of you. Darrel's customer service is second to none, and the Gunhammer does come with a lifetime warranty. *Rant alert: It is a source of constant surprise to me that people consider the warranty a selling point, and yet some of those same people never think to actually use the warranty if the knife is defective before they complain about it. Fortunately, my knife was perfect out of the box, and should serve as a good example of the type of knife you will be getting, hopefully without needing to use your warranty. So, what type of knife
will you be getting?
Unboxing
Like all HTM knives, the knife will arrive in HTM's attractive box:
I think packaging is often indicative of the company's philosophy. If it's a company which aims to provide cheap knives for the undiscerning company, they'll shove the knife in that clamshell plastic packaging that requires a really good knife to open. In fact, some of those knives that come in said packaging aren't even sharp enough to cut themselves out of that packaging. I've been known to say that such clamshell packaging is a good test of an EDC knife. Most decent production knives will come in a no-frills box with the company's logo on it. HTM's box, on the other hand, is sturdy cardboard, and even includes a distinctive geometric design. The box is actually sturdy enough for use as a gift box for jewelry or other things. To me, that confirms that HTM truly is a mid-tech company (a step above production knives in terms of quality, while not actually being a full-on custom). Most knives will come in a little foam nest. HTM provides you with the same cushioned zipper case that all DDR knives come in.
Again, the quality of the case screams quality. It's made from durable nylon fabric with nice tight stitching with good quality thread, a nice soft liner with plenty of foam to cushion your knife, and a solid zipper. The best part is that the case is actually large enough to fit a pair of eyeglasses or sunglasses. I don't ever use the case for my knives, because my HTM knives are for every day carry. However, I've used them to protect a spare pair of glasses, and they do a fairly good job at that, despite not being a hard case. The case can also fit 2 knives in a pinch, although they'll be snuggled up close, and may scratch each other.
Open the case, and you'll get your first glimpse of the knife:
The first time I looked at a Gunhammer, I thought that it looked too small to actually house a blade as large as it was advertised as having. However, Darrel's design philosophy is renowned for minimizing handle size while maximizing blade size. If you've ever seen his Madd Maxx folding dagger, you'll realize that it takes a designer with a lot of skill to design a full-on dagger that can fold up and still be small enough to be portable in a (large) pocket. That same skill went into the Gunhammer's design. Press the flipper, hold on tight, and out pops a surprisingly large blade.
Be warned, Darrel's Assisted Opening Mechanism has a lot of oomph to it. I usually have to warn people to hang on tight when they deploy the knife, because it can actually kick itself out of your hand. Of course, once you've opened the blade, you're probably hoping to cut stuff. So, let's talk about the blade!
The Blade—Grind, Geometry, and Performance
The blade on this knife is 3.5” of satin finished M390 super steel. For the metallurgically inclined among the readers, M390's composition is 1.9% carbon, 20% chromium (which makes it stainless), 4% vanadium, which contributes to wear resistance and hardenability (which may account for why M390 can be tempered to 62 HRC, while popular steels like S30V usually run around 58-60 HRC), 1% molybdenum (which prevents brittleness, and allows maintains steel strength at high temperatures, which means it has a high austenizing temperature and may form the other part of the picture that allows higher HRC than most steels), .7% silicon (for strength), .6% tungsten (contributes to better wear resistance), and .3% manganese (for grain structure and hardenability). M390 is a powder metal, which I believe gives it a finer grain structure, which may contribute to M390's ability to take a fine edge. It has a higher wear resistance than S30V or CPM 154 while retaining a high corrosion resistance, but has a lower toughness overall. I think the major advantage to M390 over the S30V models I've used before is that it is much easier to sharpen, and takes a very fine polish (although I prefer a micro-serrated edge on my user knives), but retains that edge for a very long time. Those features make it a good choice for an every day carry knife, and the fine grain structure and ease of polishing make it a good choice for a mid-tech folder as well. I found the following chart from
www.simplytoolsteel.com to be interesting, and reproduced it here for your reference as well.
The geometry of the knife is excellent as well. The bowie and torpedo blade shapes have almost identical curvature, which seems to work well for a normal cutting motion: your hand will travel maybe 2.25” horizontally, while you get the full 4” length of the edge against the surface you're cutting. However, the bowie blade has a very slight recurve, so it may have slightly better cutting ability in a draw cut.
The new grind on this knife is lower than on the earlier torpedo rendition I have, which has a very high grind. It's now .75” up the blade, instead of a full inch. I generally prefer higher grinds, but I think this one makes sense for the M390, particularly since it may help provide better lateral strength (although you should still never pry with your folding knife). The blade is also thicker, at nearly 4mm thick, compared to around 3mm for earlier models.
I believe the edge angle on a stock Gunhammer is 35 degrees, which provides for a nice slicy edge. Mine came razor sharp, and even after nearly 2 months of carry and moderate use without ANY resharpening or stropping at all, is still sharp enough to shave!
The finish on the knife is excellent as well. You can spot some very faint grind marks upon a very close inspection in the right light, which are generally much fainter than the far more visible ones on my Benchmade 950 Rift or any Spyderco knife I've ever seen. It's definitely clear that the finish quality is much higher than on any production blade that I've ever seen, and the overall finish has an even look that appears to be generated by media blasting or something similar. I prefer stonewashed to any other finish, but this one is very smooth, and probably enhances cutting ability and corrosion resistance. Of course, one possible downside to such a smooth finish on an EDC knife is that oils and dirt show up much more clearly against the surface. It cleans up pretty well if you rub it with one of those cloths for cleaning eyeglasses, but if you use it like I do, it's so pretty that it almost feels a shame to smudge it. The grinds are perfectly even, and the tip profile from the back of the blade is perfect:
There's also jimping on the back of the blade. The jimping is fairly thin and closer together than on previous models, and gives very good grip to your thumb.
Performance is excellent. I've cut probably 500 strips of cardboard with it over the past couple months, and it can still easily pushcut paper, shave, and perform other tasks. I've used it for a wide variety of tasks for the past few months, including whittling, cutting zipties, and the bowie blade provides good penetration with the point. And, it can handle those pesky thick plastic clamshells with ease. I'm impressed that, after 2 months of every day carry, it can still easily cut paper and shave. And, at the point of starting this review, I hadn't touched the edge up at all; all this is still with the factory edge!
Then I tried it out on some leather, so I could see how clean the cuts were. Here's the result:
Well, cardboard, paper, and shaving are all popular city EDC tasks, but I wanted to give it a tougher test, so I tried out some tough .25” manila rope. The fibers on such a rope are a good test for an EDC knife. I was able to push cut it through the entire rope with a fair amount of force:
However, on a draw cut, it only severed 2 of the 3 strands, despite enough force to cut a fairly deep gouge into the bamboo cutting board.
I next tried running the blade over the bamboo cutting board repeatedly for about an hour and a half while I watched a movie, so as to dull the blade. The repetitive movement had a couple bad side effects—I got a cramp in my hand, and my wife slugged me in the arm really hard at the end of the movie. The edge, unfortunately for my review purposes, was STILL shaving sharp, although there were some barely perceptible blips on the edge that I at first thought were slight chips, but when I brushed the edge off on the leg of my pants, they went away. Curses! I ended up running the sharpmaker gray rod over the edge to dull it, so I could test ease of sharpening. I returned the edge to shaving sharpness in a matter of a few minutes. I'm actually really impressed with M390. It's a very good steel, although I suppose that I won't try any prying abuse due to the overall lower toughness.
