How kitchen knives are made

A cheap kitchen knife is cut from a rolled steel sheet like a cookie from dough, then hardened.

stations: 6
things upstream: 36
raw sources: 16
steps from the ground: 7

The short version

Most kitchen knife blades are either stamped or forged. Stamped blades are cut from a sheet of cold-rolled steel, heat-treated for strength, then ground, polished and sharpened. Forged blades are hammered hot, quenched and tempered. A handle is fixed on at the end.

Stamp out the blade shape

A press cuts blade-shaped blanks from a sheet of cold-rolled steel. Stamped blades often lack the thick collar called a bolster, which is one way to tell them from forged ones.

Goes in
Stainless steel
Harden in the furnace

Blanks go through a furnace and a quench so the steel turns hard enough to hold an edge, then a gentler reheat takes away the brittleness.
Grind the bevels

Abrasive belts take the flat blank down toward its edge. The cross-section can be a straight wedge or a hollow curve, which decides how food slides off.
Polish the flats

The sides are buffed smooth so the blade looks even and resists sticking and staining.
Fit the handle

Scales of wood or plastic are riveted to the tang, or a handle is molded on, and the blade is checked for balance.

Goes in
Lumber
Hone the edge

Fine wheels or stones give the final edge before the knife is cleaned and packed.

End of the lineKitchen knife

Worth repeating

Carbon-steel kitchen knives hold an edge well and contain about 1 percent carbon.
Stainless knife steel is roughly 10 to 15 percent chromium, which resists rust.
Ceramic knife blades are made from sintered zirconium dioxide, which stays sharp for a long time but is brittle.