2. The main types of knife edges
In general, it is more accurate to classify grinds and cutting-edge shapes into two main categories: knives with a V-shaped, straight cutting edge and knives with serrated blades.
Picture 1. V grind
Picture 2: Serrated blade - wavy edge grind
When examining various knives and their types of cutting edges, it is important to recognize that there are more than just two categories. Globally, there are three primary types of cutting edges, as well as some hybrids that combine different sharpening techniques.
Picture 3. Saw-tooth blade
2.1. V-shaped (straight) cutting edge grind
Plain cutting edge grind is the most widely distributed and commonly used type of edge on various knives of different purposes. This traditional cutting-edge grind type has stood the test of time, demonstrating its ability to effectively cut a wide range of materials. Blades with a plain cutting edge are known for producing clean cuts and leaving even edges.
Picture 4. V-shaped blade grind
The term "V-shaped cutting edge" refers to geometry of the apex and the overall appearance of bevels, which ultimately define the cutting edge.
Picture 5. Geometry of a v-shaped blade grind
Assuming that the cutting edge is a perfectly straight line is an oversight. In truth, the edge of a classic symmetrical double-beveled blade may reveal minute imperfections akin to tiny saw teeth when viewed under a microscope, depending on the precision of the edge machining. These microscopic details can affect cutting performance on different materials and under various conditions.
You are most likely to find a flat v-grind edge on flat knife blades used for household purposes such as food preparation in the kitchen, outdoor activities like hunting and fishing, and for camping. Common foodstuffs handled with these knives include meat, fish, vegetables, fruits, as well as various packaging materials and other things.
The technique for using a flat blade knife typically involves pressing and pulling the blade in a single direction to achieve clean cuts, as seen when slicing steak or extracting a piece of sushi from a fish carcass.
It is common to find the flat cutting edge grind on survival and tactical knives utilized by law enforcement agencies and the military.
These knives have a straight blade and a plain edge to facilitate various tasks, including chopping, for which another blade type may not be suitable.
Sharpening a blade with this type of cutting edge is often straightforward and in most cases even a beginner can cope with this task.
2.2. Wavy cutting edge
The serrated edge, as indicated by its name, features a series of evenly spaced hollows that facilitate efficient cutting of foodstuffs. It is common to find this bevels type on bread knives designed for cutting bread but can also handle a variety of other foods.
Picture 6: Blade with wavy grind
It is particularly effective for cutting foods with a soft interior and a tougher outer layer, such as thick-crusted fried meat, cakes, pies, and even pineapples, serrated knives offer practicality and convenience.
In addition to standard bread knives, there are specialized sandwich knives with flat partially serrated blades. These knives are the best for cutting fresh bread with a hard crust without damaging the appearance of the product. It is worth noting that serrated edges are typically created on single bevel blades for optimum cutting performance.
Picture 6.1. Blade with a wavy edge, plain side.
Picture 6.2. Blade with a wavy edge, bevel side.
The benefit of using a serrated blade over a flat blade grind is the reduced effort required for cutting, as the sharp tips initiate most of the cutting action. With a gentle back-and-forth motion, the blade effortlessly slices through the food product, offering a different cutting experience than a traditional chef's knife.
Various manufacturers offer steak knives, vegetable peelers, tomato knives, and hard sausage slicers with slightly different wavy teeth sizes, yet the fundamental principle remains the same.
If you have ever attempted to cut a tomato with a V-shaped and serrated blade, you likely understand the clear difference in ease and effectiveness.
You might be curious about how to sharpen a serrated knife. Fortunately, sharpening such a blade is relatively straightforward. All you need is a honing rod with a diameter that matches the serration pattern of your knife or a standard water bench stone with a rounded corner for precision sharpening.
2.3. Saw or serrated cutting edge
This type of cutting edge is similar to serrated wavy grind, but the "teeth" are designed more like those found on an ordinary saw blade.
Picture 7: Blade with a saw like grind
The size and shape of these teeth can vary depending on the knife's intended use and the manufacturing techniques of different companies.
Picture 8. Saw tooth setting
It is important to note that knife blade serrations do not get tooth setting, and they are in one line with the main bevel of the blade. Additionally, serrations are typically present on only one side of the blade and are not symmetrical. Asymmetrical grind, as shown in images 6.1 and 6.2, is common for knives with this type of cutting edge.
In some cases, blades feature a combination of a double-edged cutting edge along half of the length, transitioning into a partially serrated edge closer to the hilt.
The cutting technique for such a blade involves smooth and steady back-and-forth motions, allowing the serrated part to excel in its cutting performance.
Knives equipped with a serrated cutting edge are versatile tools capable of handling a variety of tasks, much like blades with a wavy grind. These knives are adept at cutting through a range of food items, including various fruits, vegetables, and meat products.
Picture 9. Kitchen knife with serrated grind
Moreover, this type of grind is not exclusive to flat kitchen knives, but can also be found on a variety of specialized hollow grind blades featuring hollow bevels. A very typical example - is knives designed for cutting parachute slings and several rescue service hollow grind knives that feature hollow bevels paired with full serration.
Within the realm of folding knives, a significant portion consists of blades with serrated edges, including those with full serration or combined grind. If you research catalogs of the famous brands, you will notice that nearly all fully serrated blades have concave or hollow bevels.
Recognized for achieving exceptional sharpness, hollow grind blades are esteemed for their precise geometry.
In the context of folding knife blades, hollow bevels are strategically employed to minimize the thickness of the bevels and create the serrated edge at the smallest thickness behind the edge and apex of the blade, enhancing overall cutting efficiency. Only hollow bevels symmetrical on both sides of the blade can deliver this result.
Picture 10. Rescue knife blade
Sharpening these hollow grind serrated knives requires ample sharpening expertise and a specific set of tools.
2.4. Combined or partially serrated grind
A partially-serrated grind is a combination of the two grind types we talked about earlier: flat and serrated. Knives with blades of this kind are often positioned as survival knives and as tactical and military knives.
Picture 11. Knife blade with combined grind
The concept of a blade featuring this particular cutting edge is to enhance its versatility and enable it to tackle a variety of tasks. The design of such a blade typically incorporates a flat cutting edge that begins at the tip and transitions to a serrated edge closer to the hilt, covering about two-thirds of the blade length.
However, the drawback of this design is that each grind type covers only a fraction of the blade length, leading to some limitations in use. Practical tests show that a short serrated segment may not always be as effective, depending on the type of serrations.
A prime example is cutting through a car belt; if a serrated segment cannot effortlessly slice through a half-inch rope or a car belt in a single pass, its usefulness may be limited. The cutting technique also plays a significant role, as the serrated section should initiate the cut, with the flat section completing the task efficiently.
Regrettably, many manufacturers often include serrated edges on knives primarily for aesthetic purposes. In some cases, these blades may feature a very short saw-like section at the blade's edge, which proves to be impractical in real-world use. This signifies a lapse on the part of the manufacturer, indicating a lack of field testing of the knife and insufficient attention from the designer regarding the knife's intended purpose.
There are several misconceptions surrounding serrated blade edges, but when crafted correctly, they can cut effectively and can even do whittling. However, these blades tend to be more challenging to sharpen and require thorough cleaning to remove any debris or food residue.
2.5. Micro-serrated grind
This type of serrations, featuring approximately 1-millimeter teeth segments, is commonly seen on vegetable slicing and peeling knives, steak knives, and lower-cost bread slicing knives.
Picture 12. Micro serrated blade edge
These knives are perfectly usable, but there is one issue. They often put this grind on cheap and low quality steels. Sharpening this knife blade types can be challenging and, in some cases, economically impractical.
Picture 12.1 Micro serrated blade, microscope view
3. Selecting the right blade for your specific needs
When considering whether to use a knife blade with a flat, serrated, or combined edge, it is important to understand that there is a specific blade grind type best suited for each type of work.
For household kitchen use, where various tasks require different knives, a classic flat blade is likely sufficient.
However, if you are planning an extended trip or preparing for unexpected situations, a serrated or combined edge may come in handy.
Different knives feature a range of cutting edges, each offering unique technical solutions that cater to practical utility and design preferences, sometimes sparking debates.
When selecting a knife, there are no definitive guides on how to choose the best one; the key advice is to have a clear understanding of your intended knife usage.
There is no clear guide on how to choose the right knife; the key advice is to have a clear understanding of your intended knife usage.
Professional knives require professional sharpening. One of the best sharpening solutions are manual guided sharpening systems. TSPROF offers a range of such systems:
- TSPROF Pioneer compact sharpening system for household knife sharpening;
- TSPROF K03 Pro professional sharpening system for knife makers and sharpening businesses.