Understanding Blade Grinds
A blade grind refers to how the cross-section of a knife blade is shaped — how the steel transitions from the spine to the edge. The grind type profoundly affects cutting performance, edge durability, and behavior in different tasks. Understanding blade geometry is one of the most important aspects of knife selection, yet often overlooked by casual buyers.
Think of blade grinds like tire treads — different patterns optimized for different conditions.
What Is a Hollow Grind?
A hollow grind features concave (curved inward) bevels on one or both sides of the blade. Instead of the steel tapering in a straight line (flat grind), the material is scooped out in a concave curve. This is created by grinding the blade against a rotating cylindrical wheel.
Looking at the cross-section: the sides curve inward from roughly the midpoint toward the edge, creating an extremely thin edge geometry with thicker steel near the spine.
Types of Hollow Grinds
- Full hollow grind: Hollow extends from edge to spine — thinnest possible geometry
- Partial hollow (scandi): Flat primary bevel transitions to hollow near edge
- Short hollow grind: Small hollow near edge atop flat/convex primary bevel
Advantages of Hollow Grinding
- Exceptional sharpness: Thinnest possible edge, extremely sharp out of the box
- Reduced drag: Material release improved — food slides off the concave surface
- Ease of sharpening: Thin edge geometry sharpens quickly
- Aesthetics: Concave flats catch light beautifully
Disadvantages of Hollow Grinding
- Edge fragility: Thin edge prone to chipping and rolling under hard impact
- Not ideal for hard use: Chopping and batoning damage a hollow-ground edge faster
- Re-sharpening complications: Hollow eventually diminishes, requiring re-grinding
Common Uses for Hollow Grind
- Straight razors (classic application)
- Hunting knives (excellent for skinning)
- Many production pocket knives
- Chef's slicing and carving knives
Other Common Grinds for Comparison
- Flat grind: Straight taper from spine to edge — versatile and durable
- Convex grind: Curved outward — most durable for hard use
- Scandi grind: Single flat bevel, no secondary — loved by bushcrafters
- Chisel grind: Single-sided grind, like Japanese kitchen knives
How to Tell If Your Knife Has a Hollow Grind
Run your fingernail from spine to edge. On a hollow-ground knife, your nail will touch the flat, then suddenly drop into the concave hollow. On flat-ground, it transitions smoothly.
Hollow grinding produces the sharpest, thinnest edge geometry. It's ideal for slicing but less suitable for hard use. Most production knives use hollow grinds for balance of sharpness and manufacturing efficiency. Understanding your grind type helps you use your knife properly and avoid damage.