How to Put a Sharp Edge on Your Favorite Knife

Knives and cutting tools have been inseparable from humans for a long time. Early man made and used primitive knives over a million years before he controlled fire. He may have lived in a cold cave and cursed the dark, but he had a knife.

The earliest knives were made of stone chips or sharp shells used for slicing or scraping, but knives quickly evolved to become essential for obtaining and preparing food, as well as for protection, and survival. Knives in different forms not only influenced man’s early development, but also his evolution. Today, cutting tools are integral to everything humans do from food preparation to spacecraft.

Knives need to be sharp to be useful. I know a knifemaker who is fond of saying, “A dull knife is just a chisel with a nice handle.” Knives also need to be sharp to be safe. Dull knives require an inordinate amount of force to cut and excessive force is difficult to control which makes them unsafe. Even dull is sharp enough to cut you.

For the outdoors person, there are endless products available for sharpening and maintaining knives. Choosing one can be daunting. No matter what sharpening method is used, an important thing to keep in mind is the bevel on the blade. This bevel is the angle that is formed where the sharpened edges meet. The angle is chosen by the maker for the particular purpose the knife or tool is designed. For durability, such as for a chisel that shears metal, a large angle of 60 or 70 degrees works best. An ax might have a bevel of 25 or 30 degrees. A narrow angle of 16 to 18 degrees, such as on a fillet knife, is for slicing. Most knives fall in between these extremes. Matching the existing bevel is the easiest way to sharpen a knife quickly and maintain its original function. Altering the bevel involves more work and changes how it performs.

Consistency Sharpens Best

For most people, including hunters and anglers, sharpening freehand is harder than it looks and as common as knives are in our lives, few people feel comfortable with the process. Initially, people do well by maintaining a consistent angle, but then as they relax, they change the angle and this dulls the edge they have created. Sharpening this way requires skill and practice. An effective way to practice without ruining a high-dollar hardened steel knife is to stop by the local thrift store to buy a handful of stainless knives for a few dollars. These are made of softer steels and are easier to sharpen which makes them perfect for honing your skill. When sharp, they can serve another purpose. I keep these cheap knives on board my boat as bait knives. These are for the use of my fishing buddies who have a habit of putting them down on the gunnel where they slide overboard.

A tip for seeing if your sharpening angle is consistent is to darken both sides of the blade an eighth of an inch with a Sharpie. Where the black becomes shiny, the blade is being sharpened. This highlights flaws in your sharpening technique that you can easily fix. To get a knife exceptionally sharp, it should be sharpened until a burr is formed. When this burr, or fine wire edge, is removed with a leather strop or belt it leaves a razor-sharp edge. A safe test for sharpness is to slice the edge of a single sheet of newspaper. If it cuts cleanly without dragging, it’s usually sharp enough.

If you are impatient and want a sharp blade quickly, there are faster ways to achieve this. Sharpeners are available that maintain a consistent angle throughout the process. One design consists of a frame that clamps on the back of the blade with different size slots or holes for different bevel angles. A rod that’s attached to a stone is inserted in one of the holes and this guides the sharpening stone across the blade edge at the selected bevel. These are moderately priced between $50 and $60 and perform effectively with a wide range of knives. Good results can be obtained in 10 or 15 minutes while watching the news. Most of them come in a small case and are emminently portable.

Bladesmiths and professional knife makers use electric belt grinders that make quick work of creating and sharpening knives. They also cost several thousand dollars. Fortunately, smaller and more affordable versions of these electric grinders are available that do roughly the same thing. One of them, made by WorkSharp, has small belts in different grits. The frame has a guide that holds the blade at the correct angle, so the belt grinds a precise bevel when the blade is drawn across it. Depending on how dull the blade is, sharpening can begin with a coarse belt and end with a fine one. Users get the best results by lifting slightly when the point of the knife reaches the belt. This keeps the bevel consistent and avoids thinning the point. These types of electric belt grinders are available for between $50 and $100. Small belt sanders used for woodworking can also be used for sharpening knives, but they need a tool rest that is adjustable.

Don’t Let Blade Get Really Dull

Dan Splinter of SharpeningSupplies.com, a company that supplies all things related to cutting tools, suggests sharpening frequently, but lightly. He cautions, “Don’t let a knife get really dull before sharpening.” He adds that, “This is why you see butchers pause frequently and stroke their blades down both sides of a round sharpening steel. It straightens the edge that rolls over without removing a lot of metal.” Dan also suggests hunters and anglers have two sharpeners. The first is a basic one, such as a rod and clamp type or electric grinder for putting a solid bevel on a blade and the other is a small ceramic or diamond pocket sharpener used for touching up a blade in the field.

Knife makers are currently in an “arms race” to develop the perfect knife steel, one that holds an edge, is tough, sharpens easily, does not rust and is affordable. According to Dan at Sharpening Solutions, “There is no magic steel that does everything. They are all a compromise. When you gain one attribute, it’s at the expense of another.” In the industry, there are approximately 20 different elements that steel makers can add to bring out different qualities. Carbon makes it hard, chromium resists corrosion, molybdenum promotes toughness, etc. Combining all the desirable qualities is like the old saw, “Choose any two of these: speed, quality or price.” Edge-holding is associated with hardness, which is associated with the amount of carbon. A knife steel that is harder tends to be more brittle and challenging to sharpen. Softer steel is easier to sharpen and less brittle but doesn’t hold an edge as well.

New developments in metallurgy have managed to combine some of the more desirable characteristics into different knife steels. Several combine edge-holding and corrosion-resistance but are hard to sharpen and expensive. Others have various combinations of qualities that are good choices for their intended purpose. A knife used around salt water for slicing, that has good edge-holding and corrosion resistance, might not need the ability to chop vigorously. A survival knife might need to be tough, easy to sharpen and corrosion proof. Most of these new high-tech knife materials perform very well but are more expensive and their features are combined in ways that favor different purposes.

This gives the outdoor person more options to choose from, but when selecting a knife material, the performance characteristics of the steel should match the intended use. A good alternative to spending hundreds of dollars for a knife, is to select one with moderately hardened steel that holds an edge well but is easy to sharpen and affordable. It may require only routine cleaning and oiling and if it’s accidentally dropped overboard or lost in the woods, it’s not the end of the world.

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• This article was featured in the May 2025 issue of Florida Sportsman magazine. Click to subscribe

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