Tops Steel Eagle cutting into car door panel. A very useful tool in times of need. ©ML Ayres.

Sharpened Prybar or Slim Slicer?

by James Morgan Ayres

Medium sized knives in the six to eight inch range are neither fish nor fowl. Too small to be a big knife with chopping ability, too big to have the carrying convenience of a small knife; what is their purpose? This size knife came into widespread use as a result of extensive studies done by the U.S. and British War Departments during War II. Those studies were carried out to find a replacement for War I trench knives. The trench knife was seen as being too large and cumbersome for modern soldiers who were primary armed with rifles. However, it was clear that a need for a fighting knife existed. The studies showed that a seven-inch blade was the minimum length required to reach vital organs through uniform clothing. Both the KA-BAR the Fairbairn-Sykes designs were influenced these studies. So are many of today’s designs.

Even if today’s designers don’t know the antecedents of their own designs they continue to build on the previous generation, turning out seven-inch knives for soldiers. They are not wrong to do so. The studies that were carried out 50 years ago are still valid. Longer knives will serve better in actual hand-to-hand combat, no disagreement on that point. But since such conflicts are relatively rare in modern warfare, soldiers won’t carry big knives, certain special ops units aside. They will, for the most part, carry a KA-BAR or something else in that size range. However, given the continuously changing nature of warfare, even that may change. As related in a subsequent section, a Marine in Iraq is known to have dispatched an enemy with his four-inch bladed tactical folder. His experience is not totally unique.

Becker Knife & Tool Model BK. ©ML Ayres.

In the civilian world there is little to recommend the medium sized knife. Most civilians will be better served with the little knife/big knife combination as discussed in the previous chapter. The only medium sized knives I carry and use these days are those that are in some way exceptional. Or I use them for instruction. Further, the only professional knife users I know who use the seven-inch length are former military. In other words we’re operating from habit, not need.

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The thick versus thin question also got started with the military in War II. It was well understood by the organizations that studied the question that a thin bladed knife would kill as efficiently as one with a thick blade, perhaps better. After all, they had centuries of experience to guide them. If you ever have the chance, visit the arms and armor collections in Paris and London. Not only will the outing be enjoyable for any aficionado of the blade, you’ll learn some things, as did I. The swords and daggers of the 16th century up to the age of the firearm were not thick or heavy. They  were thin, light and fast. As an aside, so is the the Kris forged in Mindanao today, a short sword that can take a man’s arm off with little effort.

The problem faced the war departments of WW II was that they had no way to produce the enormous quantities of steel needed for the war effort. High quality blade steel was almost unobtainable. The solution was to use lower quality steel and make up for the lack of quality by using thicker blades.

There was an additional reason to use thicker blades. Given that bladed weapons were no longer primary in warfare, a knife issued to the troops would have to also serve as a utility tool. Thin, whippy swords do not make good tools for ripping open ammo crates, cutting steel packing bands, opening C-Ration cans or tearing through building walls. Thus was born the KA-BAR and other knives like it, combination weapons and utility tool. This legacy influences knife design today. I think that’s a good thing. Next Page