One of the most common questions I get from students of knife tactics is, “What type of edge is best for a personal defense knife—plain, fully serrated, or 50/50?” Like most equipment choices, it ultimately boils down to a matter of personal preference. However, there are some solid guidelines that can help you decide what’s best for you.
First of all, let’s assume that we’re talking about a dedicated personal defense knife, not one that will be used for utility purposes or even do double duty in both roles. We’re concerned with pure combative use.
Also, as far as I’m concerned, we’re only talking about true, committed cuts. I know that some edged-weapons instructors advocate tactics with serrated edges that are based on raking or “scaling” exposed skin, but I’m not in that camp. If you are using a knife in a fight, it should be in defense of your life. As such, you should be trying to stop your attacker decisively, not just inflicting arbitrary pain.
With all that in mind, our goal is to choose an edge that cuts as efficiently as possible in the context of typical defensive applications. That means something that cuts tissue effectively, but more importantly, something that will power through typical clothing and still have telling effect on the anatomical targets underneath. To evaluate edge performance in this context, I use a target I call “Pork Man.” It consists of a raw pork roast that I butterfly and tie around a wooden dowel with butcher’s twine. I then wrap the roast with about 20 layers of plastic kitchen wrap and “clothe” it with a denim pant leg, a jacket sleeve, or something similar. This provides a consistent simulation of tissue, bone, tendon, skin, and clothing and a basis for reasonably empirical cutting tests. I have used this type of target for over a decade in numerous cutting tests and demonstrations with all types of knives. That live-blade cutting experience is the basis for my observations in this column.