Piston Chakki, also known as "Piston Flour Mill", is a type of traditional flour mill commonly used in India and other South Asian countries. It is an improved version of the conventional stone chakki, where the grinding is done by a piston rather than a stone. In a piston chakki, a piston is used to grind grains such as wheat, rice, or maize into flour. The piston moves up and down, rotating a set of horizontal grinding stones, which crush the grains against the stationary grinding stone. The flour is collected in a container placed below the grinding chamber.

Piston chakkis are popular in rural areas because they are relatively easy to operate and maintain. They are powered by a diesel or electric motor, and can be used to grind a variety of grains, including hard and soft wheat, rice, corn, and millet. The flour produced by piston chakkis is generally coarse and can be used for making traditional flatbread such as roti and chapati.