15 April 2009

EDC Knives: Tactical Folder Design II

Continuing on from my last post, here I will be briefly looking at tactical folder lock and carry designs.

Lock Design

I’m not going to even attempt to describe or illustrate all the various locking systems, but the Benchmade website covers them all. Lock design is concerned with both safety and ergonomics. Safety is obvious, but ergonomics because the lock should allow the operator to manipulate it with the using hand (i.e., one handed).

Some locks are located on the side or back or the knife handle. These are desirable from the perspective that the operator does not have to put thumb or fingers in front of the blade when closing the knife (if you know what you’re doing!). If fingers before blade is a real concern, make life easy and buy a knife with an axis lock, like the SOG Flash I mentioned last post or one of the many Benchmade AXIS-equipped models.

Note that while Benchmade says lock back knives take two hands to close, if the lock in the center of the handle spine (as is regular for tacticals), they can in fact be closed with one hand. Spyderco describes the most common technique here (YouTube demonstration), but you can also just pinch the handle between thumb and middle finger, and then release the lock with your index finger. This is necessary with blades that lack a kick (unsharpened base) and otherwise keeps your fingers away from the blade.

However, the most popular lock design is the liner lock, which does require the operator to put thumb in front of blade to push in the liner and close the knife (see right). It sounds scary, and takes a little practice, but countless users do this daily and closing accidents are not a serious concern. But if that makes you nervous, again, go with a different design.

What about lock strength? First, realize that blade lock strength is really only a concern in thrust cutting (stabbing). Otherwise, all mechanisms that keep the blade from closing work about equally well. Even for thrust cutting, any properly-designed lock will hold under typical stresses. However, many cheap knives user liner locks that are either quite thin or badly aligned with the blade axis. I'd trust a cheap back lock over a cheap liner lock. But I'd trust any style of lock on a modern, well-made knife.

One last consideration is potential for accidental lock disengagement. This is virtually a non-issue for axis lock knives, another of that design's strengths. However, if you grip a back lock knife badly, you could depress the lock release. For this reason Spyderco cuts a scallop in the lock release on many models which makes that less likely (the "David Boye dent"). Similarly, it is possible to accidentally release a liner lock with a tight and bad grip. CRKT’s AutoLAWKS dual-locking system prevents this. It takes a little more technique to close a LAWKS knife one-handed, but it is one of the strongest lock designs currently available.

(L-R) A Benchmade axis lock knife, a CRKT M-series knive with AutoLAWKS, and a Spyderco back lock with David Boye dent.

Carry Design

Spyderco is commonly credited with creating (or at least popularizing) the pocket clip, now found on almost all tactical knives. The clip is used to attach the knife to the inside of the front pant's pocket. Some knives allow the clip to be repositioned on the knife, on either side for left or right side carry, or even on either end for blade tip up or tip down carry.

Tip up/down carry makes a difference in opening the knife. For me, tip up opens easiest, since with the way I draw, tip down I have to reorient the knife in my hand to open it. However, some manufactures believe tip down carry is safer, and mount their clips that way (e.g., CRKT, on most models). Most users of course prefer a knife tapped for mounting the clip either tip up or down, left or right, like many Spydercos.

However, another consideration is where the clip is located relative to the ends of the handle scales. If mounted at the very end, again like my SOG Flash I, this allows "deep carry," with only the clip visible on the outside of the pocket and no handle exposed. If the clip is lower down on the handle, of course more handle will stick out of your pocket. This make your draw easier, but also may be more prone to snag and also advertises that you are carrying a knife. All this is purely preference, and most users will quickly find out theirs. I prefer deep carry, tip up.

Next up: Blades

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