Knife Blade Shapes 101

Knife Blade Shapes 101

 

by Bob McCauslin

 

There are many blade shapes; each with its own strengths and weaknesses. Though modern knife manufacturers strive to add something new to the market, in one form or another, they all originate from one of these standard blade shapes.

The bottom line up front: there is no single blade shape that is ‘best’ for all uses.

This article is intended to help you choose one or more blade shapes that will best satisfy the needs you have.  The most common blade shapes are listed below with some discussion points on strengths/weaknesses you may want to consider.  When choosing the best knife for your needs, always consider the blade type, blade material, and handle material to ensure the total package aligns with your intended use and any limitation(s) you may have.

One quick note up front: when used, ‘pocket knives’ refers to a folding knife where the blade will fold at a hinge and nest into the handle, and ‘fixed blade’ refers to a knife that does not fold.  When choosing a pocket knife, I always recommend a locking mechanism for safety when the blade is exposed.

 

 

(Blades shown are just pictures of blade types – not name brands of knives we necessarily recommend. This article is simply to teach you the difference in blades and their uses. Other articles will differentiate steel quality and manufacturers.)  

 

 

The normal (or straight-back) blade shape:

 

 

This blade generally has a wider, dull, flat back and a curved cutting edge.  The back is not sharp allowing you to use your other hand or fingers to apply additional pressure and increase the cutting force.  The wide, dull back also adds a little extra weight to the blade making the knife heavy and strong for its size. The curve also concentrates force on a small point, making cutting easier.

Overall, this is a good for slicing or chopping (most fixed blade chef’s knives and many fixed blade hunting knives are of this shape).  I recommend this blade shape for kitchen and hunting uses, and it is the basic general-purpose blade for many pocket knives.

All other blade shapes are modification to this shape.

 

 

The trailing point blade shape:

 

This knife has a back edge that curves upward. This lets a lighter-weight knife have a larger curve on its cutting edge (or belly). Such a knife is optimized for slicing or slashing.

Because of the larger cutting area, trailing point shapes are common on skinning and fillet knives.

The large belly on a trailing point knife makes it perfect for slicing and skinning. With the high point up and out of the way, it also makes the perfect shape for filleting meat away from a bone.  Most ‘fish and fillet’ knives are of this shape and every fisherman needs one in their tackle box.

However, the up-swept point also frequently makes it a much thinner blade tip and therefore gives this shape a weak point which is susceptible to breakage unless constructed of highly-flexible surgical steel (therefore quite expensive).  Trailing point blades are a poor choice for survival knives.

 

 

The clip-point blade shape:

 

A clip-point blade is like a normal blade with the back ‘clipped,’ usually concavely formed (but can be a relatively straight cut) from about the half-way spot on the blade’s spine to the tip making the tip thinner and sharper. The back edge of the clipped area may also have a false edge bevel that could be sharpened to make a second edge.

The sharp tip is useful as a pick, for piercing, or for cutting in tight places. (If the false edge is sharpened it increases the knife’s effectiveness in piercing.) The ‘Bowie knife’ style fixed blade usually has a clipped blade (some are quite pronounced). This is a popular choice for survival knives.

Being a good all-purpose blade, clip-point blades are common on pocket knives, though usually with a less-pronounced clipped area. The clip-point shape gives you a very sharp, controllable point.  It is great for thrusting and piercing.  This shape provides a long belly edge for slicing and slashing.  I recommend the clip-point for a general-purpose pocket knife but caution not to use the tip for prying due to breakage issues.

However, just like the railing point shape, the tip is narrowed and can be weak and susceptible to breakage.

 

 

The drop-point blade shape:

 

The drop point blade is another great all-purpose blade and is one of the most popular blade shapes in use today. It uses a convex curve on the back of the knife near the tip which is the opposite of the clip-point which 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 due to its effectiveness in most applications.

The drop point is very popular on hunting knives because of the controllable point (to avoid accidentally nicking internal organs during field dressing) and a large slicing belly line which is quite effective in skinning. This is a popular choice for survival knives.

The drop point provides a strong point that is sharp and controllable.  It has a large belly line for slicing and slashing. I highly recommend the drop-point blade for general-purpose pocket knives

However, the point of a drop point is not as sharp as a clip-point which makes it less suitable for piercing.

 

 

The spear-point blade shape:

 

The spear point is a symmetrical blade in that is curved the same on either side of the spine which runs down the center of the blade vice on its edge. The point is in line with the spine.

Spear-points may be found single-edged (with a false edge), double-edged or may have only a portion of the second edge sharpened (usually the front half). A spear point provides a very strong tip, though the tip itself is only sharp when both sides are honed.  Throwing knives usually have spear-points but some may be only flat pieces of metal without the spine.

The Spear Point has a strong point due to the enter spine, sharp point when double edged, and very controllable by the user, especially for thrusting and piercing. Survival knives can be found in this shape due to its center-spine induced strength and multipurpose ability to be made into a spear.

However, it presents a small cutting belly edge making it less suitable for slicing and slashing.  When both edges are sharpened, it can present the threat of self-inflicted wounds if not used with care.

 

 

The pen blade shape:

The pen blade is commonly found on most smaller pocket knives.  These were previously referred to as ‘pen knives’ due to their past primary use in sharpening quills for writing.

The pen blade is similar in shape to either the spear point blade with a more gradual curve, or the drop-point blade.  Pen knives are usually quite small, though it is being used more frequently to refer to somewhat larger pockets knives which are usually of the drop-point variety.

Pen blades are most commonly used in day-to-day activities such as opening mail.

 

 

The needle-point blade shape:

 

The needle-point is a symmetrical, sharply tapered, twin-edged blade often seen in fighting blades, such as the Fairbairn-Sykes commando knife. Its long, narrow point offers good penetration but is highly liable to breakage if abused. Although often referred to as a knife, this design may also be referred to as a stiletto or (slender variety of) dagger due to its use as a stabbing weapon, albeit one very capable of slashing as well.

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 needle-point is very thin and has a sharp point providing the ultimate in piercing soft targets.

However, the slenderness of the point makes it susceptible to break when it encounters a hard target.  Additionally, the tapered point eliminates a typical belly line making it unsuitable for slicing except for extreme close combat.

This blade shape is not recommended for the average individual.

 

 

The spay-point blade shape:

Center Blade

The spay-point takes its name from the tool it was designed to be for spaying animals.  It has a single, mostly straight edge that curves strongly upwards at the end to meet a short, dull, straight clip from the dull back.

With the curved end of the blade being closer to perpendicular to the blade’s axis than other knives, and lacking a piercing point making penetration unlikely, spay-points are highly suitable for skinning applications.

However, the lack of a serviceable point makes the spay-point a poor choice for a general purpose knife whenever your daily activities require a piercing action.

 

 

The tanto style blade shape:

 

The tanto blade has a somewhat chisel-like point that is thick towards the point (being close to the spine) and is thus quite strong. It is superficially similar to the points on most Japanese long and short swords. 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, but the tip can be hard to control.

The Westernised tanto is usually straight but have a slight curve. The point is actually a second edge on the end of the blade, with a total edge angle of 60 – 80 degrees. Some varieties may have the back edge angled to the point slightly and sharpened for a short distance from the point.

Note: many tanto blades have chisel grind meaning that only one side of the blade is beveled. This will tend to make longer cuts curve.  I recommend against the chisel grind blade, but some swear by it because it halves the sharpening time.  You may want to experiment with one and make up your own mind.

The tanto blade has an extremely strong point and is great for piercing hard materials and is generally breakage resistant if the construction steel is of good or better quality. They are becoming quite popular in certain tactical knives.  I highly recommend the tanto for this use provided it isn’t of chisel grind manufacture.

However, the loss of the belly makes it unsuitable for slicing.  It can also be hard to control the point.  Due to the control issues with the tip making self-inflicted stabbing injury high, I don’t recommend a tanto for your general-purpose pocket knife if you are a novice knife user.

 

 

The sheepsfoot blade shape:

 

 

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 wide, dull back and were originally used for trimming the hooves of sheep.  Great for chopping but lacks a sharp point.

The main purpose of a sheepsfoot is for cutting and slicing where a point is not wanted or needed and is the distinctive blade shape used on santoku chef’s knives and I highly recommended it for kitchen applications.

The sheepsfoot also provides the closest thing to a razor blade or box cutter type of cutting experience in the standard knife shapes.  If you need long, straight cuts, this is the blade shape for you.

The sheepsfoot is great or holding the spine with your fingers, providing a great degree of control.  It is the most controllable shape for slicing and chopping commonly found in stores. The lack of a true point prevents accidental stabbing.

However, no true point exists so it is inappropriate if that is your need.

 

 

The Wharncliffe blade shape:

 

 

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 less of an angle.  These blades were typically used by sailors at sea since the shape of the tip was designed to prevent him from stabbing himself when being jolted about by the waves.

Unless you need a knife for use in heavy seas, I recommend avoiding the Wharncliffe blade.

 

 

The Ulu blade shape:

 

Also referred to as an Inuit woman’s knife, it is a sharpened segment of a circle. This blade type has no point and has its handle in the middle.

It is good for scraping, and sometimes chopping. It is the strongest knife shape for these purposes due to the handle being directly above the blade rather than at the end. The semi-circular version appears elsewhere in the world as a ‘head knife.’

Ulus are used in leather working both to scrape down leather (reducing thickness), and to make precise, rolling cuts for shapes other than straight lines.

The Ulu blade is a superb kitchen tool for a variety of uses and I recommend having a couple in your home and camp kitchens.

 

 

The gut hook blade shape:

 

A gut hook blade is a special type of blade in which the spine has a sharpened semi-circle ground into it. Used by hunters for field dressing; the ‘hook’ in the spine is placed into a small cut laced in the underside of the game animal and then pulled to open the skin for field-dressing your game. The small hook opens the abdomen of the animal without slicing into the muscle or viscera, preventing contamination and maintaining the quality of the meat.

The gut hook configuration is designed specifically for hunters, making field dressing wild game easier and more sanitary. The large belly is perfect for slicing or skinning.  Every game hunter needs to carry one when on the hunt.

However, the ‘hook’ in the spine is challenging to sharpen, and if dull, it loses much of the gut hook shape’s benefit.

The bottom line reiterated: no single blade shape is ‘best’ for all uses.  There are a couple ‘best general purpose’ blade shapes mentioned above.  They are the most commonly used blades for pocket knives and fixed blades because they have proven themselves to be suitable.  This guide is intended to have you determine what you want to use your knife for first, and then review to find the blade shape that best matches your needs.

We will discuss types of edges – plain, serrated and 50/50 – and spine serration in a future article.