Through the multiple episodes I've watched, I've heard judges use the terms obtuse and acute along with referring to "The geometry of the knife." This intriguing phrase captured my attention because I'd never thought of geometry being associated with knives. This term refers to the grind used on the blade or how did they make the sharp edge.
The edge itself is made up of two parts. The first part is the edge bevel which takes the thickness down from the top or spine down to almost the edge. The second part is the micro bevel which finishes off the process. The angle of the micro blade determines the use of the knife. If it has a edge between 35 and 40 degrees, it is often found on an axe while an edge of 25 to 30 degrees is associated with a utility knife. Pocket knives usually have a micro edge of about 15 degrees while cooking knives are between 15 and 20 degrees. Finally a razor blade is often around 10 degrees.
The grind is the type used to create the edge of the blade and there are eight a knife smith can choose from. The first, the hollow grind, is a very popular one and has been for centuries. This grind is a concave one where the two sides of the blade curve in to a point, symmetrically. Unfortunately, it tends to dull quickly and isn't the strongest edge but it is the edge you see on cutting knives.
Next is the asymmetrical grind which uses two different lengths of sides and can combine two different grinds. One of the most popular asymmetrical grinds uses either convex grinds or flat grinds. Using two different grinds produces a more durable edge with a decent sharpness to it. This grind is often found on tactical knives.
The third is a flat grind which comes in three different types. The flat grind is the easiest and simplest one possible. One is the full flat grind in which both sides are cut with the same angle to create a V shaped. It is most often found on Chef's knives because it provides an extremely sharp edge, good for pushing the knife into something. Unfortunately, a full flat grind may provide a sharp edge but it is not very durable and a true full flat grind is not often found today.
The second type of flat grind is the high flat grind and is more popular because it leaves a small part of the blade with the same thickness and is located near the handle on the bottom of the blade. This is a good knife to use for survival because it is easy to sharpen anywhere. The last type of the flat grind is the Scandi flat grind which is similar to the high flat grind but the part where the thickness is the same is longer.
Then there is the convex grind where the bevelled part pushes outward some rather than inward like the hollow grind. Although the edge stays sharp longer and is more durable, it is much harder to sharpen due to the slight outward bulge in the blade. This grind is associated mostly with axes.
The compound grind begins with one grind and then adds a second V bevel to make a cutting edge. This is the most common grind done today on knives because the edge cuts better and does not chip as easily. The chisel grind has only one side of the edge sharpened to between 25 and 30 degrees that starts in the middle while the other side remains flat. Aside from being found on chisels, this edge is often found on Japanese cooking knives.
The final grind is the semi-convex grind which is also known as the asymmetrical convex grind which puts the convex edge and V edge together. This is not a particularly popular grind but it is seen once in a while. I found it interesting to learn all this. Let me know what you think, I'd love to hear. Have a good day.
No comments:
Post a Comment