Post by Lobster on Jan 30, 2016 23:27:04 GMT 3
The Knife Blade
The Spine
The spine is the top or opposite side of the cutting edge and is usually blunt
The Clip / False edge
The clip helps to make the tip of a blade thinner and increases the ability for penetration. Clips can be straight or curved.
The false edges is mostly a design feature and help reduce weight on large blades but they do also help penetration.
False edges are found on many blade designs, not only on clipped knives.
The Belly
The belly of a blade is the curving section of the edge. Some knives like tantos do not have a curving section, others like trailing points are mostly curve. The belly increases the knife's ability to both slice and slash. It presents an ever-changing angle to the material being cut, and this means slicing efficiency is preserved across the cut.
If slicing and slashing are important to your task, look for a nice curving belly. However, there are always trade offs. Usually, the more belly a blade has, the less acute the tip. So for better slicing you lose piercing ability. Trailing point skinner knives are basically all belly, because you do nothing but slice with them.
To a degree a knife maker can manipulate the trade off between slicing and piercing by clipping a blade with lots of belly and add a false edge to make the tip a bit sharper.
The Recurve
When the edge of a blade is S-shaped, it is called a re-curved blade. The recurved belly has a longer cutting edge and slicing forces the material into the edge. It is a great slicer/slasher , and in a big knife it can make for excellent chopping geometry as well.
The downside of this design is that it is rather difficult to sharpen.
The Tip
The tip is the forward part of the blade and it includes the point. .
The Point
The point of the blade is where the spine and the edge of the blade come together. It is what the knife pierces with. To pierce really well, there needs to be as little metal as possible up front, so a piercing point is thin and incredibly sharp. But the thinner the point, the weaker it is. A dagger has a thin point, sharp on both sides to decrease the profile. The tanto has a very strong point, due to the spine being full thickness very close to the point. This means it won't penetrate anything like a dagger into a soft target, but the massively strong point can survive a thrust into a very hard target that would break a dagger point. Again, knife makers can manipulate the trade off between strength of the tip and its ability to pierce, for example by grinding a false edge into a point to make it pierce better.
The other important decision about the point is where to put it. Some knives place the point down almost at the edge like sheepsfoot blades. Trailing point blades, often used by hunters for field dressing game put the point way up high and out of the way. Knives whose points require maximum control like a defensive knife want the point to be in line with the users hand. This usually means the point must be below the spine of the blade. There are a number of blade styles achieving this, drop point, clip point or hawkbill come to mind.
Blade designs
1 Straight back
The spine runs straight from the handle all the way to the tip of the blade. The cutting edge of the blade curves upwards creating the tip. A good allround blade with great chopping, cutting and slicing abilities. Decent for piercing, often used in large knives and machetes.
2 Trailing Point
A trailing point knifes spine and edge curves upward. Trailing point blades provide a long curved belly tapering to a fine point making them ideal for slicing, chopping, skinning, filleting and other delicate work. The tip tends to be weak.
3 American Tanto
The tanto knife with its chisel edge draws inspiration from Japanese swords and is praised for its extreme piercing abilities through tough materials. The front edge of the tanto knife meets the spine at an angle rather than a curve. The tanto blade does not have a belly making it not ideal for slicing but has a very strong tip that can be used as a chisel or scraper.
4 Clip Point
The spine of the blade runs straight from the handle and stops about halfway up the knife here it moves downwards in a curved or straight line to the tip of the blade. The "missing part" is called the clip. This style of blade was made popular by the Bowie knife. It has a very sharp and controllable tip that helps also with cutting in tight spaces, great for piercing and the pronounced belly makes cutting, chopping and slicing easy. The tip is not as strong as other designs.
5 Drop Point
The spine of the knife runs from the handle to the tip of the knife in a slow downward curve. The drop point has an easily controllable point helping with dressing game and often has a pronounced belly that helps slicing and chopping. The tip is strong but not as sharp as other designs making it not the best piercing blade.
6 Dagger
A dagger is a double-edged blade excellent for stabbing or thrusting. The spine of the blade is sharpened like the edge and lets the knife cut in on both sides. Some daggers often have a false edge on the spine of the blade that looks like an edge but is not sharpened. The tip is not as strong as other designs.
7 Spear Point
A spear point is a symmetrical blade with a tip that in line with the center line of the blade's axis. They can be single or double edged, although the tip is only sharp if both edges are sharpened. Spear points have a strong tip, most throwing knives are spear points.
8 Sheepsfoot
A sheepsfoot edge is straight and the spine curves down from the handle to meet the straight edge making a false point. The sheepsfoot blade is for cutting and slicing where a point is not required or desired. Because the back spine is not sharpened, it can be held with your fingers, providing a great degree of control. The straight edge makes clean cuts and there is minimal risk of stabbing injury. Doesn't pierce or stab well.
9 Wharncliffe
A similar blade to the sheepsfoot but the spine starts to curve much earlier leading into a much more pronounced tip. This blade is very utilitarian and often used by construction workers who appreciate the control of the blade, the fine point and straight cutting edge and the ability to work in confined spaces. The tip is not as strong as other designs.
10 Hawkbill/Talon
The spine and edge curve downwards tapering into a sharp curved tip. This design is excellent for cutting materials like rope, line and webbing and the ability to insert the curved tip into tight spaces with great control make this blade it a good choice for rescue knives. Due to its shape it is easy for long straight cuts through cardboard, carpets and similar materials. Hawkbill blades also have their place in martial arts and self defense knives. Due to the curve of the edge chopping is not as easy as with other designs, the tip is relatively weak.
Blade finishes
Mirror finish is a finish that literally reflects like a mirror. The high polish and smoothness in this type of knife reduces cutting drag and makes the knife easy to clean. This finish ususlly provides optimum corrosion resistance. On the downside, a mirror finish shows scratches very well and it is expensive to produce.
Polished finish is similar in appearance to a mirror finish, but it is less reflective. A polished has the same pros and cons like a mirror polished blade.
Satin finish is the most typical knife finish. It is slightly less shiny than a polished finish, and it is less expensive than both the mirror and polished finishes. It has decent corrosion resistance.
For a Stonewash finish, the blade is tumble finished with pebbles and then smoothed. This finish hides scratches well so the blade might not need to be polished as often as others with different finishes.
Slightly more prone to corrosion due to the rougher surface.
A Bead Blasted blade is dull and non-reflective. The steel is blasted with plastic beads to reach the desired effect. Like stonewash, this finish hides scratches pretty well, but due to its rougher texture it is therefore more susceptible to corrosion.
Coatings provide good corrosion resistance, but they eventually scratch and wear off. A very common coating is Titanium Nitrade (TiNi) found on many production knives. Daimond Like Carbon (DLC) is a very durable coating usually found on higher priced blades. Other coatings include Powder Coating and Paint but those tend to wear off very quick.
The Spine
The spine is the top or opposite side of the cutting edge and is usually blunt
The Clip / False edge
The clip helps to make the tip of a blade thinner and increases the ability for penetration. Clips can be straight or curved.
The false edges is mostly a design feature and help reduce weight on large blades but they do also help penetration.
False edges are found on many blade designs, not only on clipped knives.
The Belly
The belly of a blade is the curving section of the edge. Some knives like tantos do not have a curving section, others like trailing points are mostly curve. The belly increases the knife's ability to both slice and slash. It presents an ever-changing angle to the material being cut, and this means slicing efficiency is preserved across the cut.
If slicing and slashing are important to your task, look for a nice curving belly. However, there are always trade offs. Usually, the more belly a blade has, the less acute the tip. So for better slicing you lose piercing ability. Trailing point skinner knives are basically all belly, because you do nothing but slice with them.
To a degree a knife maker can manipulate the trade off between slicing and piercing by clipping a blade with lots of belly and add a false edge to make the tip a bit sharper.
The Recurve
When the edge of a blade is S-shaped, it is called a re-curved blade. The recurved belly has a longer cutting edge and slicing forces the material into the edge. It is a great slicer/slasher , and in a big knife it can make for excellent chopping geometry as well.
The downside of this design is that it is rather difficult to sharpen.
The Tip
The tip is the forward part of the blade and it includes the point. .
The Point
The point of the blade is where the spine and the edge of the blade come together. It is what the knife pierces with. To pierce really well, there needs to be as little metal as possible up front, so a piercing point is thin and incredibly sharp. But the thinner the point, the weaker it is. A dagger has a thin point, sharp on both sides to decrease the profile. The tanto has a very strong point, due to the spine being full thickness very close to the point. This means it won't penetrate anything like a dagger into a soft target, but the massively strong point can survive a thrust into a very hard target that would break a dagger point. Again, knife makers can manipulate the trade off between strength of the tip and its ability to pierce, for example by grinding a false edge into a point to make it pierce better.
The other important decision about the point is where to put it. Some knives place the point down almost at the edge like sheepsfoot blades. Trailing point blades, often used by hunters for field dressing game put the point way up high and out of the way. Knives whose points require maximum control like a defensive knife want the point to be in line with the users hand. This usually means the point must be below the spine of the blade. There are a number of blade styles achieving this, drop point, clip point or hawkbill come to mind.
Blade designs
1 Straight back
The spine runs straight from the handle all the way to the tip of the blade. The cutting edge of the blade curves upwards creating the tip. A good allround blade with great chopping, cutting and slicing abilities. Decent for piercing, often used in large knives and machetes.
2 Trailing Point
A trailing point knifes spine and edge curves upward. Trailing point blades provide a long curved belly tapering to a fine point making them ideal for slicing, chopping, skinning, filleting and other delicate work. The tip tends to be weak.
3 American Tanto
The tanto knife with its chisel edge draws inspiration from Japanese swords and is praised for its extreme piercing abilities through tough materials. The front edge of the tanto knife meets the spine at an angle rather than a curve. The tanto blade does not have a belly making it not ideal for slicing but has a very strong tip that can be used as a chisel or scraper.
4 Clip Point
The spine of the blade runs straight from the handle and stops about halfway up the knife here it moves downwards in a curved or straight line to the tip of the blade. The "missing part" is called the clip. This style of blade was made popular by the Bowie knife. It has a very sharp and controllable tip that helps also with cutting in tight spaces, great for piercing and the pronounced belly makes cutting, chopping and slicing easy. The tip is not as strong as other designs.
5 Drop Point
The spine of the knife runs from the handle to the tip of the knife in a slow downward curve. The drop point has an easily controllable point helping with dressing game and often has a pronounced belly that helps slicing and chopping. The tip is strong but not as sharp as other designs making it not the best piercing blade.
6 Dagger
A dagger is a double-edged blade excellent for stabbing or thrusting. The spine of the blade is sharpened like the edge and lets the knife cut in on both sides. Some daggers often have a false edge on the spine of the blade that looks like an edge but is not sharpened. The tip is not as strong as other designs.
7 Spear Point
A spear point is a symmetrical blade with a tip that in line with the center line of the blade's axis. They can be single or double edged, although the tip is only sharp if both edges are sharpened. Spear points have a strong tip, most throwing knives are spear points.
8 Sheepsfoot
A sheepsfoot edge is straight and the spine curves down from the handle to meet the straight edge making a false point. The sheepsfoot blade is for cutting and slicing where a point is not required or desired. Because the back spine is not sharpened, it can be held with your fingers, providing a great degree of control. The straight edge makes clean cuts and there is minimal risk of stabbing injury. Doesn't pierce or stab well.
9 Wharncliffe
A similar blade to the sheepsfoot but the spine starts to curve much earlier leading into a much more pronounced tip. This blade is very utilitarian and often used by construction workers who appreciate the control of the blade, the fine point and straight cutting edge and the ability to work in confined spaces. The tip is not as strong as other designs.
10 Hawkbill/Talon
The spine and edge curve downwards tapering into a sharp curved tip. This design is excellent for cutting materials like rope, line and webbing and the ability to insert the curved tip into tight spaces with great control make this blade it a good choice for rescue knives. Due to its shape it is easy for long straight cuts through cardboard, carpets and similar materials. Hawkbill blades also have their place in martial arts and self defense knives. Due to the curve of the edge chopping is not as easy as with other designs, the tip is relatively weak.
Blade finishes
Mirror finish is a finish that literally reflects like a mirror. The high polish and smoothness in this type of knife reduces cutting drag and makes the knife easy to clean. This finish ususlly provides optimum corrosion resistance. On the downside, a mirror finish shows scratches very well and it is expensive to produce.
Polished finish is similar in appearance to a mirror finish, but it is less reflective. A polished has the same pros and cons like a mirror polished blade.
Satin finish is the most typical knife finish. It is slightly less shiny than a polished finish, and it is less expensive than both the mirror and polished finishes. It has decent corrosion resistance.
For a Stonewash finish, the blade is tumble finished with pebbles and then smoothed. This finish hides scratches well so the blade might not need to be polished as often as others with different finishes.
Slightly more prone to corrosion due to the rougher surface.
A Bead Blasted blade is dull and non-reflective. The steel is blasted with plastic beads to reach the desired effect. Like stonewash, this finish hides scratches pretty well, but due to its rougher texture it is therefore more susceptible to corrosion.
Coatings provide good corrosion resistance, but they eventually scratch and wear off. A very common coating is Titanium Nitrade (TiNi) found on many production knives. Daimond Like Carbon (DLC) is a very durable coating usually found on higher priced blades. Other coatings include Powder Coating and Paint but those tend to wear off very quick.