Blade grinder

However, meat grinders (and food mills) use a scissor cutting action as the blades rotate against a perforated metal plate.

Unlike blade grinders, these mixers do not alter (break, cut, shred, macerate, pulverize) the material being mixed.

[citation needed] Blade grinders exploit a feature of propellers that is undesirable in the propulsion systems of boats and airplanes: the higher the rotation speed, the more energy is spent in shearing and cutting rather than in pushing.

Rotary lawn mowers were not developed until small engines became powerful enough to run the blades at a speed high enough to cut.

[8] Because these blade grinders frequently are used for grinding both coffee beans and spices, cleaning them well is important to prevent unwanted transfer of flavors.

Commonly found in pharmacies in China for grinding Chinese traditional medicine, the blades of this style of grinder can rotate at 28,000 rpm or more and are capable of reducing hard dried roots to powder.

Blenders are popular tools for production of purées and pastes, using both the cutting and shearing effects of high speed blades.

Blade grinder for home grinding of coffee beans and similar things
Blade on a rotary lawn mower