knifeopedia
Blade Grinding and Blade Geometry
By applying different ways of grinding, various blade geometries can be produced:
Hollow grind
In this budget-friendly grinding technique, only the lower portion of the steel blank is ground. This method is commonly used for producing very low-end knives, but it's also typical for creating serrated edges.
PROS
Inexpensive
CONS
Thick blade above grinding area = high cutting resistance
A lot of cutting drag in area of concave edge
Thin and fragile blade on cutting edge
Flat grind
The blade is ground flat on both sides to a thin edge.
PROS
Thin blade and potentially good sharpness
CONS
Thin and fragile edge
Contact of food along the entire blade = sticking and drag; more power needed for cutting
Convex grind
The blade is ground on both sides with a convex geometry. Common way of grinding German style knives.
PROS
Food contact only on small area of blade = less sticking and drag
CONS
Thicker blade in area close to edge = less sharpness
Single bevel flat grind
Adding a flat bevel to just one side of the blade. While it's a standard technique for scissors, it's uncommon for quality knives. However, you’ll often find this type of grinding on lower-cost imitations of traditional Japanese knives.
PROS
Very inexpensive way of blade grinding
CONS
Blade only works for either left- or right-handed people, not for both
Straight cuts are difficult
Single bevel hollow grind
Hollow grind on one side of the blade, paired with a bevel on the opposite side. It’s the signature grinding technique used for traditional Japanese single-bevel knives.
PROS
Very thin edge and hence very high sharpness
Generally good stability of blade
CONS
Blade only works for either left- or right-handed people, not for both
Straight cuts are difficult (which is intended for a very specific use)
Thin and hence fragile and sensitive edge
Hybrid grind
Almost flat grind on the upper part of the blade, with a convex grind in the lower third. It’s the hallmark of Japanese double-bevel knives, combining strength and sharpness.
PROS
Generally thin blade, with added stability in edge area
Best compromise between sharpness and blade/edge stability
Less sticking/drag
CONS
More expensive, since more grinding steps