Jay Fisher - Fine Custom Knives

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This page is about serrations, particularly on the modern handmade and custom knife, specifically on my knives created here in Sharp Instinct Studio in my sole authorship knives. I'll detail a little history and description of serrations and why they work and how they apply, with descriptions and photographs of my own serration styles and applications. I will explain why I've chosen a particular type of serration for a specific application, and how they work in that application. I'll describe the limitations of their use, considerations for individual knife blades, and how to sharpen the serrations on my knives specifically. I'll detail current and accessible sharpening tools and their features so the owner of one of my serrated knives can sharpen his own serrated edge sections. I do this as part of my commitment to my tradecraft, art, and professional service to my knife clients. As with most other pages of this site, when you are done reading this, I promise you will know more than most people, knife makers, and knife manufacturers about serrations on modern hand knife blades.

For detailed descriptions and discussion of other knife maker's or factory knife serrations, please contact those other suppliers and makers. 

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Serrations, History, and the Modern Knife

The word serration comes from the noun and adjective serrate. Serrate is probably a imitative variation of the Latin word serra, which means saw. The word sierra is a variation of the Latin word, so it's no wonder saw-toothed mountains are named sierras. The study of serrations is a fascinating subject, and naturalists have wondered for centuries how animal and insect teeth, as well as some plant leaf edges cut so well. Seen in modern photomicrographs, it is usually tiny serrations that are the contributing factor to the keen cutting ability of sharks teeth, saw grass, and even corn leaves and dinosaur teeth. Nature's serrations work, so we simply imitate the natural world with our own version on the cutting edges of knives.

Many modern knives have serrated blades. The reason for serrations is to aid in cutting, ripping, and tearing through tough materials that resist cutting with a regular smooth blade edge. In theory, if a regular, straight cutting edge of a knife blade is truly sharp, serrations should never be necessary. The reality is, though, many abrasion-resistant surfaces like plastics, hardwoods, textiles, and other tough modern materials are better cut with the ripping action of serrations.

The reason serrations work is because of the tremendous pressure applied to very small cutting edges or advancing teeth surfaces. I'll probably delve into this in greater detail in my book, but the concept is that through a combination of light percussion and advancing narrow cross-sections, a tooth can have a more aggressive cut than a smooth blade. Of course, a regular straight cutting edge should be clean, efficient, and smooth, and the two types together make for a very useful knife that can cut through a wide variety of materials, as  long as the knife maker has done his job right.

When I first started making knives for military combat applications, my military clients insisted on serrations that work. They were, frankly, tired of owning and trying to use knives that had serrations that were not sharp, keen, or aggressive enough. When I informed them that in order for serrations to work well, they must be thin, and therefore had a greater potential to break, their request was simple: "make a serration that works aggressively, and even if I break off a tooth, the serration keeps on working, cutting, ripping, and tearing." This is what my serrations do.

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Serration Considerations: Limitations and Advantages

Whether a knife has or (in the case of custom knives) will have serrations on the blade bears careful consideration. On my Blades page, I discuss this briefly, and here is a more detailed version. I'll give the limitations first, and then the advantages:

Serrations: Limitations and Considerations

• Serrations subtract from the overall regular straight cutting edge length of the knife. If your knife has a 6" blade, this is measured (in most states) from the tip of the point to the front face of the bolster or guard face, and not the actual cutting edge length. So the cutting edge may be 5.5" long, and you decide on 2" of serrations. You are now left with a 3.5" regular edged knife blade. On shorter blades, this is very noticeable, and can even prohibit the use of serrations altogether. A knife that has a regular cutting edge length of one inch is hardly worth a handle, unless you want a box cutter. Please consider that a fixed blade box cutter with replaceable double ended utility blades has a cutting edge length of over 1.25" and the more common retractable version has a cutting edge length of 1.125"!
• Serrations can make a knife harder to insert and tricky to remove from a sheath, depending on their design and location. Careful design cannot always help, and you might find your sheath welts ripped up from the teeth over a period of time. This is not only noticeable in leather welt sheaths, but even kydex and aluminum framed sheaths can suffer from abrasion and ripping by serration teeth.
• Serrations can not be used on the top spine of one of my tactical knives if it is to reside in a locking sheath. This is because the location of the locking mechanism is in the direct line of contact of the serration teeth if they are placed here, and the two will destroy each other. Serrations on a spine of one of my knives must be coupled with a tension fit sheath, which is less secure. A newer alternative comes from my development of my counterterrorism knife sheaths. This is a hybrid of my tension and locking sheath, simply called a hybrid tension-lock sheath. This particular sheath uses tension of a component that does not contact the serrations, but it is not as secure as a locking sheath.
• Serrations on the spine of any double-edged knife may cause other issues. For instance, if the owner wants to bear down on the regular straight edge of the knife blade, or wants to apply spine pressure with his thumb or hand (typical for tanto knife secondary points), obviously this can't be done of the serrations are there.
• Serrations on the spine of a knife require the knife to be double-edged. This means double ground, often double hollow ground, which can remove a good cross-section of the spine. To have the same spine strength as a single-edged knife blade, the blade must be wider. If kept the same width, the knife is simply weaker in the spine because there will be less metal there.
• Because serrations on the spine of the knife create a double-edged knife, certain countries may not allow these knives to be shipped or possessed. For instance, Australia prohibits the import of double-edged knives altogether.
• Because serrations require brute force to rip, tear, and cut, most of them should be called rip teeth, and they are usually placed near the ricasso, not at the end of the blade. That way, more force at the heavier cross-sectional geometry of the blade will support their use. If serrations are put near the blade tip, it's possible that when they snag, the force of the hand with the leverage of the blade length may offer enough force to snap of the tip of the blade, the weakest part of every knife. Sometimes, in specialized knives, serrations are located on the top edge, such as in specialized chef's knives, but not usually in tactical combat models. Considering this, serrations on the top edge of a double-edged knife should not start at the tip, but slightly behind the tip for greater tip strength.
• The serrations may hang up, snag, and seize in cutting when you don't want them to. You may be using your regular cutting edge, and have the material you're cutting fall into the serrated part of the blade, hanging up or snagging unexpectedly, and perhaps ripping up a clean cut or causing hesitation that is undesired. A finer serration or specially designed serration may reduce hanging and tearing, but not always.
• The tip of the teeth of narrow serrations may break off, because sharp teeth must be thin teeth. One of the military requirements I've had is to make a tooth that will keep cutting even after broken. This means a thinner cross section, to make a more aggressive tooth.
• Serrations may be difficult to sharpen. They often are, but thankfully I've included instructions to do that on this very page. I use special equipment (diamond abrasive based cutters) to make them and hone them, and that same equipment is not available in the field, but diamond abrasive coated rods and tools are. Note that each type of tooth is different, and requires its own sharpening regime.

Serrations: Advantages and Considerations

• Serrations can allow ripping or tearing through extremely stubborn materials that a straight edge can not. If a knife user encounters hardwoods, bone, horn, plastics, textiles, and even tissue that resist cutting with a straight edge, a well-designed and sharp serration can allow him to rip through. This is the main advantage of serrations on knives and it is substantial. I've even had military clients rip and saw through the aluminum on a wrecked APC to affect a rescue with serrations on my knives.
• Serrations can clear a cut. When a regular, straight cutting edge cuts, it simply displaces the material from itself, separating the material, but not removing it. So the side pressure and potential for pinching the knife blade increases as the cut deepens. Having a thin blade helps, but the material is still there, pressing on the sides of the blade. It's interesting to note that a hollow ground blade has the thinnest cross-section, so that helps. Even the thinnest blade does not remove material from the cut, and a serration may well do that. It tears and rips through, dislodging particles from the material, helping to clear the cut. No where is this more noticeable than when ripping hardwoods with serrations.Also, because the cut is rough, the material being cut can help to separate the gap.
• Serrations can pierce. They can simply start a cut that would be difficult to start with a slick, smooth, and sharp blade. Some polished or very smooth surfaces can be difficult to start cutting, and the serration point can pierce these surfaces, allowing a traditional edge cut to commence.
• A seldom considered feature of well-designed serrations is that they will prevent an enemy from grasping a blade. This may seem obscure, but this feature in serrations has been known by Armorers, weapon makers, and warriors for literally millenia. When a gloved hand tightly grasps a straight, smooth blade, no matter how sharp the cutting edge is, if it is grasped tightly, and the blade does not move along the length of the blade, the edge simply can not cut. In the warrior's combat knife, this is a devastating reality. The blade can be grabbed tightly, and perhaps even taken from the warrior. How serrations can prevent this is that, if they are well-designed, grasping the knife at the serrations will pierce even the best gloved hands, and the enemy will have to let go. In antique swords and parrying daggers, this was a distinguishing factor that prevented grasping one another's blade.
• A serration can save the rest of the edge, the blade, and possibly even the knife! For a simple illustration, try cutting through a small piece of oak with a straight edge, specifically cross-cutting (across the grain, not along it). Even the sharpest straight edge will slide along it, and then the temptation will be to start chopping on the wood like with an axe. This is not how a thin, sharp cutting edge should be used, and the likelihood of breakage is substantial. I know of plenty of knives that have been broken or had their edges chipped because they were used for chopping, instead of cutting. This does not only apply to woods; I've seen blades chipped while chopping bone. If the serrations are present, and they work, the temptation to chop with a knife is often averted, saving the blade as the serrations do the cutting necessary.
• Serrations extend the cutting surface of the actual edge, sometimes by many factors. A straight length of blade is measured simply by the distance along the edge. A serrated knife, because of the many curves, in and out of the blade axis, actually increases the cutting edge length significantly. You simply have more edge to cut with on a serrated blade section. This adds to the life of the edge.
• Serrations may outlast the regular knife blade. This is often the case, due to several factors. The serrations are simply less used than the regular straight edge length, so do not wear as quickly. Also, serrations usually wear on the higher points, that is, the most protruding parts of the teeth. So the deeper edges in the serration simply see less wear. Because well-designed serrations have thicker profiles and cross-sections than straight edges, they last longer. Sharpening is less often, and less of the serration is sharpened away.
• Serrations can help to catch, trap, or snag materials and items that are easily pulled away from smooth, straight, slick, and sharp blades. Fibrous materials like rope, line, or even some skins can simply slide away from a smooth blade, but serrated blades bite into the group of fibers and can help to trap and cut them without sliding.
• Serrations can cut effectively, even when more dull than the straight edge. This is because more pounds per square inch can be applied to a smaller area, combined with somewhat protected areas of the serrated edge. Usually the most frequently dulled parts of the serration are the points or most outward projections of the serrations, which can leave the deeper edges of the serration sharper for a longer period of time.
• Specialized serrations can be designed and made to cut aggressively in one direction and release in another. This is the function of canted (angled) serrations on knife blades. This, in design concert with mechanical aids to apply pressure in the cutting direction such as quillons, mid-bolsters, and sub-hilts, can mean a very efficient cutting direction and device.
• Serrations look more aggressive. Though I do not include serrations simply for the visual punch, they do add to the appearance of a blade in stylistic fashion. Like some mirror polishes, on tactical combat knives, they may add to the threatening appearance, perhaps intimidating and threatening an enemy more than a slick, smooth blade. Of course, this is not the main reason to include them on a knife, though some factory knives are made this way just to make the knife look more aggressive. They must, as a primary consideration, add to the cutting abilities of the knife.
• Serrations have derivatives, like line cutters, hookblades, and gut hooks. These specialized features allow specific results. A line cutter may be designed so small line (such as monofilament) may be trapped and cut with one hand, while the line slides down the arm and handle and is snagged and sliced in one motion. Without a line cutter, one hand must hold the line, and the other locate and slice with the blade using a sawing motion. A hookblade is a specialized blade that may allow cutting on the inside curve, while protecting another area of contact. This has been effective in certain rescue knives, where a hookblade feature can be used to remove a wetsuit from an injured diver without cutting his skin. Another application would be extrication and the slicing of seat belts while not cutting the victim. Clothes and even boots can be removed in emergency medical care of the sick and injured without injuring the victim with a knife blade. Gut hooks, used in hunting knives, can be used to slice the skin of an animal while gutting, yet prevent cutting the internal organs which can spoil the meat. All of these features can be interpreted as derivatives of the serration, or modified blade edge.

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Factory vs. Handmade Serrations

Just like all the other parts, components, and features of a fine handmade knife, serrations also differ from factory, manufactured, or boutique shop serrations. A close look at any serration will give a clear and distinctive knowledge of these differences and how they affect performance, service, trust, and value.

There is a major determinant factor between mass produced, factory, manufactured, or even small boutique shop serrations (even if the shop is named for a singular knifemaker) and serrations made by a custom knifemaker. That huge singular factor changes serrations simply from rough parts of a cutting edge to instrument-sharp adjuncts that amplify the cutting ability of the knife by many, many times. The factor?

Mass produced serrations are created by a wheel, a diamond coated serration wheel that has a corrugated surface and is coated with diamond abrasive in nickel plating. These wheels produce a generalized serration profile, typically just some waves, and the serrations are shallow, not pointed, washed over, unsharpened, and generally dull. They are always shallow.

Handmade serrations are made one at a time, by hand, with a file. This is done before heat treating the steel blade, followed by dressing by hand, individually after hardening and tempering the blade, followed by singular finishing, polishing, and sharpening techniques for each tooth and each depression, each convex and each concavity in the serration profile. This results in a crisp, clean set and arrangements of cutting edges throughout the length of serrations. Every micro face, every thousandth of an inch is a cutting tool: razor keen, with crisp, pointed apexes, chisels, and hooks. They are deep and effective.

Some more problems with factory serrations:

• Factory serrations are usually ground from one side of the blade. This may seem unimportant, but I believe it is a substantial difference than fine handmade serrations which are ground from both sides of the blade. The reason this is done is because it is cheap, like most things factory knife manufacturers do. Well-made serrations created from both sides mean careful registry and alignment must take place on each tooth, so that the tooth valleys and points match each other and prescribe a line down the axis of the cutting edge. This makes a much sharper serration because the included angles of two-sided serrations are almost always lower than one side serrations.
• Factory serrations are harder to sharpen. You might think that being only on one side would make factory serrations simple and easy to sharpen, but this is not the case. Lots of material will have to be removed from the one side of the blade where the factory serrations are machined in order to achieve and maintain a lower and sharper angle. With well-made double-sided serrations, a few quick strokes are all that is necessary to tune up the edges and points since they have less surface area to cut away.
• Factory serrations are uneven. Since these serrations are cut by dressed and formed wheels, usually under automated processes, it's only natural that the diamond plated grinding wheels wear down, and they don't wear evenly. So, if your factory knife is early in the production run, the contour of the serrations will be a bit more even, but if it is later in the wheel's life, they will be uneven and poorly defined. Fine handmade serrations are each meticulously laid out by hand, and tuned to each other for an even fit. While the handmade serrations are hand-made, they are much crisper, angular and agressive.
• Factory serrations are never crisp or well defined. This is due to the process limited by the machining technology. A grinding wheel, whether it is silicon carbide, aluminum oxide, boron nitride, or diamond coated nickel on steel or phenolic substrate lacks extremely sharp, punchy and well defined valleys, so the points on the serrations are always rounded and softened. Contrast this with fine handmade serrations which are clear and sharply defined because each cut is individual and independently cut and each peak comes to a definitive point. A crisp point means instant biting and trapping, one of the main reasons for serrations in the first place.
• Factory serrations do not extend up the termination of the grind. Since factory serrations are made by a machine alone, they can not be deeply machined into the grind termination near the ricasso. What this means is that they must be located where the knife blade is absolutely flat and of uniform thinness. In order to do this, the factory knife is not radiused or contoured at the termination, it is straight, flat, and squared off, making the blade to handle junction weaker. The factory serrations also must be moved away from the termination area, making them a bit further from the handle. In some cases, this means less leverage and less serration length overall. With fine handmade serrations, the placement can be up nearer the termination, even into the termination with substantial strength and cross sectional thickness at these first important teeth. This is most easily noticed when viewing the knife blade from the side.
• Factory serrations have many convex profiles. This is, again, due to the constraints of manufacturing. Wheels used to cut these serrations can not have deep valleys or peaks, only a slight variation of the two. So the design of the grinding wheel surface is simplest to have a combination of convex and concave edges. Unfortunately, a convex serration edge is the hardest for the knife owner to sharpen, and must be done with tiny, narrow dressing sticks, carefully aligned. Though convex serration profiles do have their place, for most serrations, they are not the ideal. Like a knife edge, a hollow ground or concave edge has the lowest sharpening angle and thus, the sharpest edge.
• There are never any points on factory serrations. Looking at the serrations below, you'll see extremely acute points on each tooth, particularly in my Vampire style. This is due to my history of making knives for military combat and rescue use. My military clients request serrations that work, even if the tooth is broken off. They are tired of serrations in name only, where a few gentle curves and valleys seem to be thrown on to the blade as an afterthought. They don't bite, they don't grip, and they don't tear and rip like serrations should do. Sharply pointed serrations do, and they are the most aggressive you will find. In all the years of making knives, I've never had anyone ask for "gentle serrations that are just a little more coarse than the straight cutting edge..."
• Factory serrations are never canted, angled, slanted, or arranged to accommodate the knife handle, use, fittings bolsters or reinforcements. In fine handmade knives, the serration works with the handle and blade design for specific cutting force application. For instance, in many of my Patriot pattern and knives with mid-bolster handle arrangements (see the Minuteman EL below), the canted serrations are designed to cut on pull and release on push. This is distinctly custom and based on the knife owner's use and requirements, something not offered on factory knives, boutique shop knives, or poorly made knives.
• Factory serrations may be soft! This is a seldom discussed fact about factory or poorly made knives with serrations. A knife blade is (or should be) roughly ground, with most of the material removed from the blade, all holes drilled, all machining that is to be done on the blade completed, and then followed by heat treating (hardening and tempering). That means that the serrations should also be machined, filed, cut, ground, and shaped BEFORE heat treat, followed by hand-polishing and simple sharpening after. This way, the serrations retain the temper of the blade. In poorly made serrations, they are machined and ground AFTER heat treating the blade, which can overheat the serrations, losing the temper. This is a particular concern because of the high speed of the wheel that cuts them.  A thin and narrow section of the serration (the points or the very cutting edges) will be the first to lose temper and soften. This is another reason factory serrations are left without thin areas, because they may bend in use due to loss of blade temper! In fine handmade serrations, only the sharpening occurs after heat treat, and in my knives, I finish grind and polish under water to keep the blade cool and preserve the hardness, and each serration cutting surface is sharpened by hand. The serration is harder, more wear resistant, and (in stainless tool steels) more corrosion resistant, and better all around.

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My Serration Types and Styles

There are many different types of serration grind, profile, and type of tooth and edge surface, even on my own knives, much less other knives by other knife makers, factories, manufacturers, or sources. I can only speak to my own serrations and my own experience making knives for over 30 years. There are many factors within my own knives that determine serration type, style, length, and design.

What a knife is expected to cut is one factor of serration design. The length of the serration available on the knife, the placement of the serration run, and the angle of the serration grinds and teeth are all important geometric considerations. I also consider the steel type, main grind geometry, handle support features, corrosion resistance, and sharpening service factor of serrations to produce and provide viable, useful, and dependable serrations that can be serviced by the knife owner. Because of all of these factors, serrations and their geometry varies, sometimes greatly, even among my own knives.

My Predominant Serration Types

• The most popular serration style I create is my Vampire rip tooth serration. The Vampire consists of alternating diameter of grinds (yes, just like a blade, a serration has a grind), and when you examine a pair of these grinds, the protruding teeth looks like the grimace of a long-toothed old Nosferatu. The key to the aggressive nature of these serrations is the alternating sizes of the grinds. No tooth is the same size, so each tooth will attack the material in a slightly different location, which makes for very aggressive cutting and ripping. This type is the most requested type of my serrations, and most of my military and professional grade tactical combat knives that have serrated blade areas have this type. The Vampire is easily serviced and maintained, so field sharpening is possible as a regular service aspect of the knife. Example below.
• A variation of the Vampire is the Canine. Like the Vampire, the Canine has alternating grind geometries, but the sizes are distribute in a two-to-one or two-to-two grouping instead of a one-to-one or alternating pattern. So the pair of two small grinds placed between the larger grinds gives the appearance of a dog's or wolf's front mouth, two large canines separated by smaller teeth, thus the name. It is a more aggressive pattern than the Vampire, and can be suited to longer runs along the blade length. It, too can be hand-sharpened in the field as part of the regular service aspect of the knife. Example below.
• A simpler version of serrations is my Barracuda. The Barracuda, just like its namesake, has an evenly sized run of small teeth for a smoother cut than the Vampire of the Canine. This is not as aggressive as the previous two, and lends itself well to even cutting with less ripping. Less ripping and tearing means less hanging or snagging in the cut, so this is an easier serration to use as it requires less force. The Barracuda can be easily sharpened in the field. Example below.
• Smoother still, yet very aggressive is my Micro-Blade serration. The micro blade consists of separated serration grinds with small sections of regular blade length between them. It is a serration that excels in smoothness, with less ripping, and can cut a wider variety of materials with limited tearing, ripping, and hanging. It's a great adjunct to specialized knives, like my EOD (Explosive Ordinance Disposal), bomb-tech, haz-mat, and disaster rescue team knives. It is a bit more complicated to sharpen in the field, but can be done by hand with the right equipment. Example below.
• My Piranha serrations have a smooth micro-edge but noticeable alternating concave edges, one rounded, and one with an internal chisel shaped square edge. This allows a smoother cut than the Barracuda, but more aggressive cutting than the micro-blade and improved trapping for textiles, woods, and other fibrous materials. Sharpening is a bit more difficult, as it requires a square edged stone or rod to sharpen the square concavities. I also offer this serration in a larger size for heavier duty survival, combat, rescue, and emergency response knives. See the Large Piranha example below.
• My Hammerhead is a very large and substantial evolution of the micro-blade, with deep concavities alternating with chisel-knife edges that are very stout and strong. This is a hardwood-gobbling tooth set that is very tough and resilient, and unlikely to chip, break, or dull. Being large, it's also easier to clean than tight or complex geometries, increasing corrosion resistance and easing blade care. It's very interesting that Gerber added my serration type to their knives in 2008, after I had introduced the serrations in my counterterrorism and Pararescue knives. However, like most manufacturers, they did them wrong, with cuts only from one side. This is because of the difficulty of alignment of automated serration grinders, and thus, they are too thick to be as effective as hand-cut serrations. My hammerhead serrations are the main choice of my counterterrorism teams. Example below.
• A specialized serration I use is my Theatre Curtain. Like the draping theatre curtains of old-time stage shows, the serration is a group of large convex grinds in a hollow ground edge. These are not scallops; scallops are concave with sharpened points, in essence my "Double Hollow" serrations described just below. These are actually convex, so this is why they are named "Theatre Curtain." There is some confusion here, since only a couple knife manufacturers call this a "scalloped" serration (Wusthof), but the main mass of knife manufacturers describe "scalloped" as concave geometry of repeating cuts in the blade with points, like my Double Hollow below. Currently, I'm only using this on my large bread knives, as it aids greatly in piercing and slicing hard-crusted breads while leaving a minimum of crumbs. If you're comparing serrations, you'll notice that this type of convex serration profile is coming up more and more in manufactured and boutique shop knives. Examine them closely and you'll see that they are poorly made, mostly ground on one side, making a thicker, less sharp edge. This is because they are ground by profile grinders, and they are never, ever as keen and thin as serrations on the best handmade knives. Example below.
• A smaller version of my Theatre Curtain serrations is my Mini-Curtain. These are similar to the larger version, but much smaller. Again, these are not scallops. They are made in a hollow ground edge, and because of their size, create few crumbs when cutting hard-loaf breads such as boules and braided breads as well as filled breads (meats, fruits, vegetables baked-in).
• In some kitchen knives, it helps to have extremely thin serrations with gentle, sweeping curves. This is created in my Double Hollow serrations. They are concave (hollow) in profile, and ground into a hollow-ground blade, so are extremely thin. They are useful for hard breads, flat breads, bagels, and tomatoes as well as other vegetables.
• Other styles are created individually, and I'm sure to create new ones. I'll post and describe them here as they become available, so please check back on the site, as it is continually updated.

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Use of Knife Blade Serrations

Modern knife blade serrations are used as described above, for tearing, ripping, and cutting through tough and stubborn textiles, wood, bone, horn, and plastics, where ripping speed is more important than accuracy. They are used on my tactical combat knives for trapping and severing tough cords, ripping through materials, and in combat. They are used in chef's knives for opening and piercing skins, crusts, and peeling.

You might read reviews by some that claim serrations should be far out on the belly and near the point of the knife blade, and not near the ricasso and handle. The theory behind this is that you might need a tough sawing action near the point, and a smooth cutting surface with more control nearer the handle. This may have some merit if you believe that you have greater or lesser control at a certain position along the knife blade, but in most knives, control of the blade is an issue based on the geometry of the blade and handle, the size and weight of the blade, the hand strength (or lack thereof) of the knife user, the nature of the material being cut, and the actual task at hand. All knives should be capable of being controlled, whether they have serrations or not.

The most important reason to place serrations near the ricasso of the knife is force and torque. Because serrations can hang, grab, and bite into the material being cut, the knife user will apply more force to make them move, free them up, and complete the cut. In combat knives, this grabbing force and being able to control it is critical. Because of mechanical leverage, more force and control can be applied to both use and free the serration when the serration is nearest the handle.

If you don't believe me, try this experiment. Grab the end of a three foot long bar of steel. Have a friend grab the bar with his hand very near yours. Tell your friend to try to hold the bar horizontal, as you try to force the bar to pivot downward. This will be very difficult. Have your friend then grab the bar at the far end. Tell him to hold the bar horizontal. It will be very easy for you to move the bar downward, no matter how hard he grasps it. What this demonstrates is the simple mechanics of a lever. The longer the lever arm, the less force it takes to hold one end as the other is moved. This same force mechanics applies to the serrations of a knife. If the serrations hang or trap, you must be able to apply great force nearest the serrations to free them. If the serrations are at the tip of the blade, they can bite and trap in material, and you will not be able to transfer as much direct force to free them. You must be able to free the serration or your knife blade is trapped. To transfer the most energy and force, the serrations need to be nearest the handle. This factor is easiest to realize in machine tools. Cutters, mills, and saw blades are chosen and kept as short and compact as possible to transfer the greatest amount of energy and control to the cutting edge and limit flexing. Another critical factor in knives is lateral flexion. If the blade is trapped at the tip in a serration, and a sideways force is applied at the handle, the mechanical leverage may be significant enough to snap the tip of the blade off.

There will be exceptions to this, of course. A good example is a chef's knife that has a serration length at the tip to pierce skin before slicing on the main blade. But this is a specialized knife and not a combat weapon or tool, and is not expected to experience extreme motion, forces, or impact.

Using serrations to cut depend on the knife, type of serrations, and the task at hand. If they are sharp, great force is not necessary. For example, with my Vampire serrations, usually the weight of the knife blade alone with a back and forth sawing motion will cut through most hardwoods, even rock maple. Most plastics give way easily to serrations, and rope and line are easily severed with a twisting motion. This is another reason not to have tip serrations, as twisting a trapped blade will most surely snap the serrated tip.

Some serrations are canted, that is, slanted in one direction. My Patriot knife pattern typically has this type of serration. This allows tremendous ripping force in one direction (pulling) while releasing in the other (pushing). In a knife designed with canted serrations, it is important to add extra features to apply even greater force to the teeth. This is why the Patriot has a mid-quillon supported by a mid-bolster (sub-hilt). This allows tremendous hand force to be applied to the serration.

In my Micro-Blade serrations, a different type of cutting action takes place. These are very smooth serrations, interrupted sharp blades with deep, sharp hollows. This type of serration is less likely to hang, but not as aggressive on hardwoods and tough plastics.

The length of serrations varies, but I typically don't make them any less than 1.5" of the blade run. This is because any smaller than than are not enough teeth to engage the cutting chore with sawing motion. If the style and geometry of the blade permits it, I may make serrations along an entire edge length. This may be different on each knife.

I rarely, if ever, create serrations that are both convex and concave. This is typically what you will see on factory, manufactured, and throwaway knives, and they are ground by automated contoured wheels. Most people cannot sharpen these mish-mash of geometries, and the long-term service of a fine handmade knife should be considered. I want my clients to be able to use and sharpen their works, over the life of the blade, which should be decades. More on sharpening below.

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Sharpening Serrations

Rod Sharpeners for Serrations (including line cutters, hook-blades, and gut hooks)

There are several good models of rod-type sharpeners for sharpening serrated knife blades. Most of these are tapered, so will fit a wide variety of serrated grooves and edges. Like a knife blade, the serrations should be sharpened when necessary, though this is much less frequently than the main blade edge. The best rod-type sharpeners to use for the serrations are diamond abrasive coated. Since these rods are usually tapered, they can fit a variety of serration profiles. They can be used to sharpen line cutters, gut hooks, and even the recurve area of some blades.

There are advantages and limitations for all types of diamond abrasive coated rod sharpeners, and here are some comparisons. The rods shown here are not all of the available types, and there are always new ones.

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Rod Sharpener Brands and Features

I've included some of the most common and accessible rod sharpeners here with some worthwhile facts for you to consider. Prices for these sharpeners is modest, and at the time of this writing, they can be purchased on various internet sites and sources from about $8.50 US to over $20.00 US. Details follow the picture above by brand, from left to right.

• RUKO 040-CS Straight Combination Sharpening Rod: RUKO (A Canadian Import Company and made in China) calls this a sharpening stick, and it has some worthwhile features to consider, as well as limitations. The package contains no instructions, only a list of "features." The rod is straight, not tapered, so will not fit a variety of serration profiles, only one, which is about .250 or 1/4", the main diameter of the rod. It has a flat side, which can help in sharpening small straight or possibly convex sections, and also a groove which can sharpen fish hooks if you're so inclined. The large diameter rod might be handy when sharpening gut hooks, large line cutters, and even the recurve areas of some blades, and with finesse, you may be able to sharpen combination convex-concave serrated pattern runs. The package description claims it is a 4" Combination Diamond Rod, but the actual measure of diamond coated rod that you can sharpen with is less than 3.25"! The idea for the rod handle and storage is decent: a cinch-type split barrel collet and a knurled ferrule allows you to store the rod safely inside the aluminum barrel, which has a tiny nickel plated pen clip. Unfortunately, on my model, I had to bear down with some seriously hard pressure to get the body to tighten on the rod, and even after I did, you could still tug it from the holder because it grips on the smooth, polished, plated part of the rod which is slick. The diamond abrasive particles are claimed to be Medium 400 grit, so it's quite aggressive.
• RUKO 041-CS Combination Sharpening Rod: Like the RUKO 040 above, this sharpening rod has several features and limitations. The package contains no instructions, only a list of "features." The actual rod has two sections, and is reversible. The first section has the same geometry and diameter (.250") with a flat side and a fish hook sharpening groove as the 040 detailed above. The other section has a taper which runs from .250" to .075" diameter. An issue is their description on the package card again, which claims the rod to be 4". The straight section is 2.5" long, and the tapered section is 2.5" long, so I don't know where they are getting their measurement. Perhaps they should call it a 5" rod! The barrel/collet-knurled ferrule holder grips much better than the 040 model, because the smooth, nickel-plated section is small, and the diamond abrasive coated particles will not allow the rod to easily slide. A drawback would be the very short length of the tapered rod, which is so abrupt a taper that you will be hard-pressed to get a 1/2" long stroke for your serration sharpening geometry. The whole combination idea is nice, though, so this sharpener might get you through the widest variety of serration sharpening tasks on those knives that have concave-convex serrations.
• Schrade: The Schrade serration rod sharpener (made by Taylor Brands in China) Arrived without even a descriptive card of features, in a box with a folded paper insert describing their knives. I have to note that the insert did have a section on Resharpening Your Knife, but it did not mention anything about sharpening serrations or even a word about the very sharpening rod in the package. I have to go on here, because this is a bit humorous. The sharpening description says, "hold the blade at a 107 to 157 angle from the surface of the sharpening stone" to sharpen. I suppose that because this is printed in China, we are supposed to understand, first, what a 157 angle is. Is that degrees? Because if it is, this must mean an obtuse angle measured from the side you are not sharpening... very confusing. Add to that that the angle is all wrong, and 157° would mean a 23° angle of the edge, the absolute maximum for sharpening. This would mean that the 107° angle was actually 73° from the stone! This would create a cutting edge that is nearly square, destroying the knife blade and making it the dullest possible blade in history! It's interesting to note that they spend twice the words in their "Consumer Awareness Statement" warning the owner that they are not responsible... okay, I couldn't help it; this is typical of products with an American name being made in China. The rod is the cheapest of all of these I'll describe, and it has some features and limitations. A neat thing is the hard, rubber-ish pen-type holder, which accommodates the rod for storage or use by simple taper pressure. The actual rod is fairly short, 3" long, and has an abrupt taper from about .310" to .050" which makes it way too abrupt to get that important 1/2" long stroke. The rod has about a 1" long groove for sharpening fish hooks, which is almost too short for that. But if compact is what you want, and you like short-stroking, this would be the cheapest route to go. Like the RUKOs above, it has 400 grit diamond abrasive.
• Lansky Diamond Tapered Sharpening Rod: This company sells a lot of sharpening products, but specifically, this diamond abrasive coated rod that they call a "Rat Tail Sharpener" is what I'll describe here. It's interesting to note that Lansky boasts over and again in their company profile the size and magnitude of their distribution center, and that it is located in Henderson, Nevada. You'll be hard-pressed to then find out that these products are actually not made there, or even in this country. When I received the clamshell package, a proud sticker was strategically placed, claiming "Lansky Sharpeners- 30 Years-Quality and Innovation" Hidden underneath was the required statement that these are actually made in China. Did they place their sticker right over the "Made in China" logo on purpose? Hmmm. Okay, this sharpener for serrations is a step in the right direction. The rod is actually 3.5" long, and has a more gentle and useable taper from .237"  to .067" in diameter, so that critical 1/2" long stroke is more realistic than the previous types. The diamond abrasive is finer, though they do not disclose the grit size, merely claiming "Fine Grit." I'm guessing it's about 600, but that's just a guess. They do include instructions, but they are not specific, merely claiming to "slide it straight down the rod with moderate pressure." Repeating this process often enough and you will destroy your serration profile. Advice: follow the instructions below. For the handle, Lansky has attached a butterfly (Balisong or fan) double pivot knife style handle, so the rod folds into the handle conveniently. The pivots are, unfortunately, plastic, so don't expect this to last. The handle is a bit bulky, with ribbed rubber grips that are really not necessary, particularly since they are not in outer edge contact with your hand when open, only when closed. But they are a convenient place for the Chinese to place the Lansky name (distributed in the US). The handles have a little tab and slot arrangement to stop them from sliding around when opened. This is a decent serration sharpener, at a decent price.
• DMT DiaFold Serrated File: Made by Diamond Machining Technology in Marlborough, Massachusetts, this is an actual United States company making fine diamond abrasive products right here in the United States of America. They make many of the diamond sharpening tools used in machine shops to sharpen and touch up the hardest of machine tool cutters, inserts, and ultra-hard edges. As you might expect, this is the best serrated edge sharpener, and also the most expensive, at about $20.00 US. The length of the rod is just under 4.5" long, and the taper is a gentle one, from .248" to .615" in diameter. So the critical 1/2" long stroke is possible for a greater area than the other models. The DMT serration files (file is a better name, because that is what they are) are available in a variety of grits: coarse, fine, and extra fine, so tuning a serrated section from rough to extremely keen is possible. The fine grit seems to be about 600. The handle is a butterfly (Balisong or fan) style just like the Lansky above, but has some nice features. The pivots are steel roll pins, not plastic and the handle has square detents and tabs that hold the sharpener both closed and open. In the open position, it has a double tab and socket to stop handle misalignment, and the tabs are curved and deeper than the Lansky for smoother indexing and a more solid fit. Though it is actually larger than the Lansky, it weighs about the same (no unnecessary rubbery grips). The DMT comes with ample instructions, though not as detailed as I will give you below.

So, there are the players. You may be influenced by the size, convenience, and carry possibilities of all these types, or you may actually need a fish hook sharpener with you, so none of these are exclusive.

By the way, as on the rest of the site, I don't get paid to do these reviews, don't receive free merchandise, exposure, or any benefit in any way from any company or anyone. This is not an endorsement of any kind, just a service I present to my clients, tradecraft and anyone with knife interests.

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Sharpening Serrated Knife Edges

Position the knife parallel to and at the edge of a bench or table. Place the spine of the knife (back of the blade) against the table, the point of the blade away from you, and the serrated edge to be sharpened straight up.

Please click on photo to enlarge.

Determine the diameter of the serration on your knife. Lay the sharpening rod against the serrations while looking down, and determine the area on the rod where the circumference of the rod most closely fits the circumference of the serration. On sharpening rods that have long handles, you may have to position the handle overhanging the edge of the bench or table to see this.

Please click on photo to enlarge.

Mark the rod. Once you have determined the location on the rod that matches the curve of the serration, use a permanent marker (Sharpie® or other) to mark a girdle on the rod. Continue the mark about ½" down the rod (toward the smaller end). This girdled area will be where you contact the serration to sharpen it. On some knives, the area being sharpened has a larger circumference than the rod (such as gut hooks, line cutters, and small recurve areas on the blade). In these cases, mark and use ½" length of the largest diameter of the sharpening rod possible, usually nearest the handle.

Please click on photo to enlarge.

Position the rod at the sharpening angle. On polished or brightly finished knives, you do not want to gouge or scratch the grind of the serration, only the cutting edge. To do this, gently place the rod, pointed end up, into the groove of the serration, feeling the angle that the main serration is ground. Once you can feel that the rod is laying in the main grind of the serration, lift the handle of the sharpening rod slightly. This will establish the angle of the cutting edge that differs from the main grind.

Sharpen. Lightly move the rod forward and backward along your ½" marked girdle to cut the edge of the serration. Do not use heavy pressure. Diamond abrasives work best at a light pressure, and no lubrication is necessary on any diamond sharpener. Do not lower the handle, or the diamond rod will scratch the main serration grind. Maintain the sharpening angle as accurately as possible.

Please click on photo to enlarge.

Repeat the same positioning technique and sharpen the other side of the serration if the serration has one. Some knives are only ground on one side of the serration.

Remove the burr. If you have done this properly, you can see or feel a tiny burr on the opposite of the last side you sharpened. Now, only using one light ½" stroke, sharpen off the burr. The serration should now be sharp.

Please click on photo to enlarge.

Wider serrations. Some serrations are wider than the circumference of the rod. Gut hooks, hook-blades, line cutters and other specially shaped large diameter profiles on knife blades are often of a larger diameter than the rod. To sharpen with a smaller diameter rod, use the largest diameter of the rod, usually near the handle. Establish the angle as above, and when sharpening move the rod along the entire edge, twisting the rod with your hand as you sharpen. This twisting motion will help prevent waviness on the cutting edge. It takes a little practice to get a smooth cut; take your time and clean up the burr for a final smooth edge.

Sharpening Theatre Curtain Serrations (including my Mini-Curtain) are a special case, and people often wonder how these are sharpened. The first thing to consider is that I use a high precision, extended, and complex heat treating cryogenic method that results in a blade that is in the pinnacle of condition. To the chef, this means that a curtain serration will unlikely ever need sharpening in his lifetime. These knives are not like manufactured knives or other maker's knives made from poor, plain carbon, pattern-welded (decor) damascus, or low alloy steels. They do not require constant sharpening to stay tuned up and ready to cut, and that is the first point.

However, after a generation of use, a curtain-serrated knife might need sharpened. To do this, the spine is taped off for protection from scratches, and several light draws with a diamond abrasive micro file is all it takes to bring them back to maximum sharpness. These files (the flat side of the half-round, the three-square and the square) will work into the V-grooves and over the convex areas easily. Just follow the original angles, and finish exactly like the concave serrations above. Just make sure the abrasive is diamond, as ceramic and other stones won't sharpen these T3 cryogenically treated knives!

Since it will probably be your grandkids that receive these knives, they might appreciate this information, long after you (and I) are gone. So I'll be sure to leave a copy in the Library of Congress so that they can look it up!

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