The basic parts of a knife
- knife blank
- back bevel
- working part
- thumb rise
- blade flat
- top edge
- unsharpened false edge
- cutting edge
- grind line
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Knives and any other cutting tools have different purposes. One is a metalworker, and another is a hunter – and tools will always be different. In addition to purposes, there is a difference in types of steel, section shapes of a blade, shapes of a lateral profile of a blade, as well as sharpening angles. In order to choose the right sharpening device and proper abrasive material, we prepared for you a brief information about the specifics of blades and steel.
The common types
- Flat grind (a blade with triangular cross section, often called a Scandinavian type flat grind). Due to the small edge angle and the flat bevel, the blade is perfect for cutting. The weight of such a blade is lighter than those with bevels that extend only a portion of a blade’s width. It is unsuited for chopping due to the lower strength of the thin edge. It requires high-quality materials and thermomechanical processing.
- Sabre grind. Similar to a flat grind blade, but the cutting edge has more obtuse angle, which gives greater strength and durability with a lower cutting quality.
- Hollow grind. It helps to achieve a particular thinness of an edge with a thick and durable spine. It is used on straight razors and knives, where the blade’s sharpness is required. Sometimes the concavity of bevels is associated with technological reasons (bevels are formed by a cylindrical cutting tool).
- Convex grind. An extra strong blade when chopping.
- Double bevel (it is often called the European type grind). Similar to a flat grind blade, but the edge has more obtuse angle due to the bevels near the cutting edge.
Lateral profiles of blades
- A normal blade. A blade is adapted for cutting and it’s capable to thrust.
- A drop point blade. The tip of a blade is closer to the centre of the blade and allows greater control in piercing, the blade is equally good in cutting or in piercing. The blade is a bit lighter than a blade of the same length without decreasing spine line. On the front of the spine there may be sometimes a false edge, formed by unsharpened bevels, or the second fully-fledged edge, that helps the blade when piercing to easily enter into the material being cut.
- A trailing-point knife. The blade of this type have the maximum length of an edge, which is useful when cutting soft materials. Some national knives with a blade of this type have a sharpened spine.
- A clip-point blade, having the tip closer to the centre of the blade allows greater control in piercing. By that this blade is similar to the drop-point blade, but with a a thinner, awl-shaped tip. A back bevel can also be sharpened.
- A sheepsfoot blade. The straight edge makes the blade adapted to accurately controlled cutting. The absence of the tip makes it impossible to pierce, but on the other hand the knife becomes safer. Such form have professional knives: a rigging knife, a cable knife, pruning knife, etc. Sometimes this form is found in utility knives.
- A tanto point blade. It is thought that historically it takes origin from Japanese knives, but this kind of tip was invented in the United States quite recently, by the division of Cold Steel company, primarily to reduce costs of manufacturing process. Some sources attribute its design to Bob Lum. Traditional japanese tantos had the shape of a tip № 1. Recently it becomes quite popular, especially in the version, where the cutting edge is formed by bevels from only one side of the blade (so-called chisel point). The blade is suitable for some cutting action (but the angle of the tip is inconvenient for cut), and when piercing, more force can be applied without damaging the tip. It is often used on combat knives.
- A spear point blade. The tip is aligned with the centerline of the blade's long axis, more often a double-edged blade. Mostly it’s used on daggers and knives that are more suitable for piercing than for cutting (however, this blade is used in knives for uncapping honeycombs in the production of centrifugal honey).
Knife Sharpening Angles
It is commonly supposed that the sharpening angle is the angle between the centerline of the blade and the abrasive surface.
- 1. sharpening angle
- 2. abrasive for sharpening
- 3. knife blade
- 4. knife cutting edge
The sharpening angle depends on the steel of a blade, hardness, and what are you going to cut with a knife. Carbon steel allows to set a more acute sharpening angle.
Very thin and sharp blades of high quality (very delicate handling / special tools like razors, cutters, special kitchen-knives)1220°
A good, more durable knife blades (attentive handling / they are good kitchen and hunting knives for handicraft)2030°
Standard trade knives (hunting, sometimes for cutting bones and tendons, hatchets)3040°
Durable blades (rough job, accompanied by a great effort, without sparing the edge of a knife)40° +