Okay, so I got off on a bit of a tangent or two. In truth, it was because I find it difficult to write about carrying a knife on your keychain. Frankly, I don't think you should carry a knife on your keychain, especially if you can carry a true multitool or a SAK. But, if you absolutely insist on carrying a keychain knife, there are a ton of options out there--literally, if chosen one piece for each model out there, its probably a ton. Of the Big Seven (Benchmade, Boker, Buck, CRKT, Kershaw, Spyderco, and SOG) Benchmade is on the only company without an entry into this market niche. Boker, as is always the case, has about a million different options.
There are two problems with evaluating keychain knives--first there are so many different kinds; and second, there is a ton of crap out there. You can find a keychain knife at pretty much any hardware store or gas station. There is also the issue that some people consider anything with a lanyard hole a keychain knife, even if it is a ZT350.
For purposes of this post, I am going to eliminate anything bigger than the Spyderco Ladybug. This means that the Aphid (a sweet little Benchmade design; see Benchmade, small knives ARE useful) and the Dragonfly are out. Think along the lines of the Boker Keycom (not the Subcom).
In a knife this small there are a couple of key points. First, blade steel doesn't really make a difference. You aren't going to be splitting logs with this thing so crappy steel, i.e. 420 HC, is okay. Good steel is better, obviously, but steel is not the most important criteria. Second, one hand opening, something I think is an essential part of a full-sized EDC knife, doesn't really matter. Knives this small, even with a one hand opening design, still don't open all that easily with one hand. This opens up a lot of room for more traditional designs with nail nicks. Third, pocket clips don't matter, here you need a good lanyard hole or a bail. Here is a good example of a knife with a bail instead of a lanyard hole:
Next, assisted openers, while possible, don't seem like a good idea with all of the handling and manipulation of a keychains that takes place. Finally, even though I would not consider an EDC knife without a lock, in the world of keychain knives, were tenths of an ounce count, I can forego a lock.
Instead of going through all of the choices out there, I am going to list a few that I think are standouts in the flooded field of keychain knives.
1. Spyderco Jester: If I had to chose a single knife to live on my keychain this would be it. I like the belly on this blade, a little more than what you get on a Ladybug, and I particularly like the jimping near the tip. Knives this small are hard to use, but the jimping at the tip gives you significantly more control when cutting. Think about the handle and blade size of a surgeon's scalpel--the closer you can get your fingers to the tip, the better. Unfortunately, this blade is out of production. Stainless steel handled versions will run you about $50 on ebay. FRN handles, which will hold up better on a keychain and add less weight to your carry, can be had for around $40.
2. Spyderco Ladybug, ZDP-189: This knife has no official product page and image, so no links other than this one at BladeHQ.com (I have no qualms about linking to them, they have great service and though their prices aren't the absolute bottom on the internet, they have selection that is unmatched; they were great when I was searching for a Bradley Alias II). This knife has a less useful blade shape than the Jester and lacks the tip jimping, but it has AWESOME steel and its full flat ground, which is nice. It is unfortunately, not yet on sale.
3. Benchmade Benchmite II: The rare small knife from Benchmade. It is also out of production, though with Benchmade, you never know--it could be tucked into an off shore, off brand line somewhere in the world. It is super slim and it locks in both the open and closed position, something that is nice on a keychain knife that is subject to more than the normal amount of jostling. It also has a sweet little blade shape.
4. AG Russell Ultimate Pen Knife: The ones with bails are no longer in production, but there are a ton of variations here. These are really elegant knives. I have handled two different versions in person and both were nice. Good utility blade shape, nice fit and finish, and completely, totally harmless looking. This is the knife your grandpa carries when he needs to dress up. From $30 to $80 depending on size and handle material. Good steel too for a keychain knife, VG-10.
5. Spyderco Bug Series: Everyone is familiar with these. The smallest is so small it is almost a novelty, but they do work and they are insanely cheap. If the AG Russell is what your grandpa carries when he is feeling classy, this is what you carry when you are trying to pinch a penny a little too much. From $8-$20.
Stay away from a production CRKT Shrimp, as they have received TERRIBLE reviews and feedback on EDCF. They have a lot of neat design ideas, but as is the case with many CRKT products, the fit and finish seem to be lacking. I also do not recommend the Boker Keycom. It is sharp and small, but as with many Bokers, it is flimsy feeling. It make be built like a tank but it just feels junky to me.
The final round of keychain stuff will be a general view of random stuff and a peek at suspension clips and devices.