Knife Grinds Explained — Hollow vs Flat vs Scandi vs Convex

Blade grind—the cross-sectional shape of a knife’s blade—is arguably as important as the steel type in determining how a knife performs. It affects slicing efficiency, edge durability, food release, and even how the knife feels during cutting. Yet grind geometry is often overlooked by knife buyers who fixate on steel compositions and ignore the shape that actually meets the material being cut. Understanding the four primary grind types—hollow, flat, Scandi, and convex—will help you choose the right knife for your specific tasks and sharpen it correctly.

Flat Grind (V-Grind): The All-Rounder

The flat grind is the most common grind in modern knife making and for good reason—it offers an excellent balance of slicing performance, edge strength, and ease of manufacturing. In a flat grind, the blade tapers from the spine to the edge in straight lines, creating a V-shaped cross-section. There are several variations: a full flat grind extends from the spine all the way to the edge; a saber (or partial) flat grind begins partway down the blade, leaving a thicker spine section; and a high flat grind begins very close to the spine, behaving similarly to a full flat.

The full flat grind is the gold standard for all-purpose cutting performance. It creates a thin cross-section that passes through material with minimal resistance, while the straight geometry is straightforward to manufacture and sharpen. Most modern EDC knives use full flat grinds: Spyderco popularized them in the production knife world, and virtually every premium folder now features some variation. The trade-off is edge durability—the thin geometry at the apex is more susceptible to chipping under lateral stress than more robust grinds. For general EDC use, food prep, and light outdoor tasks, the flat grind is ideal. For heavy chopping or prying, it’s underbuilt. Saber grinds retain more steel behind the edge for added strength at the cost of slightly reduced slicing efficiency, making them popular for “hard use” knives from makers like Cold Steel and Zero Tolerance.

Hollow Grind: The Slicing Specialist

A hollow grind uses a concave (inward-curving) wheel to create a blade that’s extremely thin behind the edge—sometimes as thin as 0.005 inches—while maintaining a thicker spine. This geometry produces the sharpest-feeling edge of any grind type because there’s so little material to wedge through whatever you’re cutting. Hollow grinds dominate straight razors, traditional pocket knives, and kitchen knives where ultimate slicing performance is the priority. The thin edge separates material with minimal effort, creating that satisfying “falling through food” sensation.

The hollow grind’s weakness is edge fragility. That paper-thin cross-section behind the apex chips more readily than any other grind type when subjected to lateral stress or impact. Hollow grinds are also more challenging to sharpen on flat stones because only the edge and the shoulder of the grind make contact—the hollow portion cannot be laid flat. This means freehand sharpeners must maintain the angle carefully, and guided systems work particularly well. As the blade is sharpened repeatedly over years, the edge moves up into the thicker portion of the grind, eventually degrading cutting performance. This isn’t a practical concern for most users—it takes decades of sharpening to meaningfully change the geometry—but it’s worth understanding. For a gentleman’s folder that opens envelopes and slices apples, a hollow grind is sublime. For a camp knife that splits kindling, it’s wrong.

Scandi Grind: The Woodworking Champion

The Scandinavian grind (or Scandi) is a flat grind with no secondary bevel—the primary grind goes all the way to the edge apex. This creates a wide, flat bevel that’s exceptionally easy to sharpen (lay the entire bevel flat on the stone) and provides excellent control for woodworking tasks like carving, feather-sticking, and bushcraft. Popularized by Swedish knife makers like Mora and Finnish puukkot, the Scandi grind is the traditional choice for woodcraft in Nordic cultures, and it excels in that role. The wide bevel acts like a chisel plane when carving, allowing precise control over cutting depth and direction.

Where the Scandi grind struggles is pure slicing. The thick cross-section behind the edge—there’s no secondary micro-bevel to reduce wedging—means a Scandi-ground knife requires more force to push through materials like cardboard, meat, or fruit. It’s a specialist’s grind optimized for wood, not an all-purpose geometry. Scandi knives are also prone to edge rolling in soft steels because the very acute edge angle lacks support. The fix is a micro-bevel: adding a tiny secondary bevel at a slightly more obtuse angle strengthens the edge while retaining most of the woodworking advantages. Many experienced bushcrafters apply a micro-bevel to their Scandi knives for exactly this reason. The Mora Companion is the quintessential Scandi knife and an excellent way to experience the grind without significant investment.

Convex Grind: The Tough Survivor

Convex grinds curve outward from spine to edge, creating a continuously rounded cross-section that’s strongest at the edge apex. This is the geometry of an axe and the preferred grind for hard-use outdoor knives where edge durability trumps slicing efficiency. The continuous curve eliminates the sharp transition between the primary bevel and the edge that creates stress concentration points in flat and hollow grinds. Instead, forces are distributed smoothly through the blade’s cross-section, making convex edges dramatically more resistant to chipping and rolling. A convex-ground knife can baton through knotty wood, chop through bone, and withstand abuse that would destroy other grinds.

The trade-off, predictably, is slicing performance. The wedge-shaped cross-section requires significantly more force to push through material than a flat or hollow grind. Convex knives feel “dull” compared to thin-ground alternatives even when they’re properly sharp—the geometry creates more resistance. Sharpening convex edges requires different techniques: a slack belt on a belt sander, sandpaper over a mousepad or soft backing (the “mousepad method”), or freehand stropping on a loaded leather strop. Standard flat stones won’t work for establishing the convex profile, though they can be used to apply a micro-bevel. Many survival knives and premium outdoor blades (Bark River, Fallkniven, Busse) use convex grinds because the use case—chopping, batoning, processing game in the field—demands durability over slicing finesse. For a one-tool survival knife, convex is arguably the best choice. For a kitchen knife or EDC folder, it’s counterproductive.

Choosing the Right Grind for Your Use Case

• EDC folder for general use: Full flat grind. Best balance of slicing and durability.
• Pocket knife for food and light tasks: Hollow grind. Ultimate slicing satisfaction.
• Bushcraft and woodworking: Scandi grind. Unmatched carving control.
• Survival and heavy outdoor use: Convex grind. Maximum durability.
• Kitchen knife: Full flat or hollow grind (Western); convex for traditional Japanese single-bevel.

Frequently Asked Questions

Can I change my knife’s grind type?

Converting a flat grind to a convex or hollow grind requires removing significant material and is essentially a professional regrind service that costs more than most knives. Adding a micro-bevel (a tiny secondary bevel) is practical and changes edge behavior without modifying the primary grind geometry.

Why do so many traditional pocket knives use hollow grinds?

Hollow grinds were historically easier to produce on rotating grinding wheels—the same wheels used for everything from straight razors to scissors. The thin edge geometry also delivered the best slicing performance from the relatively soft carbon steels used in traditional knife making. The inferior edge retention of soft steels was compensated for by making them cut as efficiently as possible.

Is there a “best” grind type?

No more than there’s a “best” vehicle type. A flat grind Ferrari doesn’t work on a Farm-Use convex grind truck road, and vice versa. The best grind is the one optimized for what you actually do with your knife. Most EDC users are best served by a full flat grind; it’s the most versatile and least specialized option.

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