The normal (or straight-back) blade is pretty straight forward – it has a dull flat back and a curved edge. Because the back is not sharp it allows you to use your hand or fingers to apply additional pressure to increase the cutting force. Overall it’s good for slicing or chopping. Still, the dull back adds a little weight to the blade so these knives tend to be a little heavier.
The clip-point blade is formed when you take a normal blade and ‘clip’ the back which results in a thinner tip. This thin tip can be used to cut in hard to reach places and provides some additional control. A Bowie knife is a classic example of a knife with a clip-point blade. Usually the clip is concave but it can also be straight.
The trailing-point blade has a distinctive back edge that curves up which allows for improved slicing ability. The large curve is often referred to as a “belly” and a large belly is particularly useful for skinning. The curve allows for a more lightweight knife as compared to the normal blade. This blade style is also popular on filet knives.
The drop-point blade uses a convex curve on the back of the knife near the tip which is the opposite of the clip-point that uses a concave curve. The convex curve is less suited to piercing but provides more strength than a clip point. You’ll find many modern pocket knives today having drop point blades as it’s effective in most applications.
The spear-point blade is symmetrical in that is is curved the same on either side of the spine which runs down the center. They can be sharp on both edges or only on a single edge which is common for penknives. Typically you will find spear-point blades on daggers and other knives designed for thrusting or throwing.
The needle-point is also symmetrical but tapers much more sharply and therefore is not particularly strong but can be used effectively to pierce or penetrate. Stabbing is the needle-point blade’s strong point and you tend to see this blade mostly on daggers intended for close range combat just like the spear-point.
The spey-point obtained its name from being used to spey animals. It has a straight edge that curves upward at the end with a relatively small clip on the back. This type of blade does not really provide a point and hence not good for penetrating but very effective for skinning animals.
The tanto knive has a chisel edge inspired by Japanese swords which provides excellent strength. The tanto name originally referred to the tip of a broken samurai sword which was very effective at piercing armor. Tanto knives have no belly so will not be able to slice but instead make up for it with tremendous tip strength that can penetrate almost anything. You’ll find some different varieties of tanto blades and they are becoming quite popular in certain tactical knives.
The sheepsfoot blade is almost the opposite of the normal blade by offering a sharp straight edge and a dull back which is largely straight then curves at the end. These knives can be closely controlled by your fingers being placed on the dull back and were originally used for trimming the hooves of sheep. Great for chopping but lacks a sharp point (which can be a plus in many situations as it prevents accidental stabbing).
The Wharncliffe blade is a thicker blade but very similar to the sheepsfoot but the back begins to curve towards the tip much earlier and therefore at a more slight angle. These blades were typically used by sailors as the shape of the tip was designed to prevent the sailor stabbing himself as a result of being jolted about by the waves.
The pen blade is typically found on smaller folding pocket knives and similar in shape to the spear point blade but with a more gradual curve. One side is sharp and the other dull just like you find on Swiss Army and similar pen-knives.
