The Pellet Mill Mechanics is a machine used to produce wood pellets from readily available biomass materials (wood chips, sawdust, planer shavings, etc.). The machines vary in size, from three kilowatts to 375 kilowatts (five to 500 horsepower) or even larger. The production volume per pellet mill ranges anywhere from 90 kilograms to eight metric tons per hour. Loose raw materials can be compacted from about 100 kilograms per cubic meter to 650 kilograms per cubic meter for an incredibly dense and efficient energy source.

Pellets are produced in the mills by pressing the raw material against small round holes in the die. The material is pressed against the die and into the holes by the roller until reaching the desirable length. At this point the pellets are cut by a knife outside of the die and fall into a storage area. Before all of this happens the raw material is treated in the mill's conditioner which may be utilized to add liquid to the raw material. This process enhances the machine's capacity and results in firmer pellets.

Pellet mills generally contain one of two die types: the flat die or the ring die. The size of the holes in the die range from two to ten millimeters. The die plate's thickness determines the durability of the pellets and may be as thick as 100 mm. These components are commonly made from metal alloys, stainless steel or chrome. This is to withstand high pressures within the die which may reach up to 172,000 kPa (25,000 psi).

In a pellet plant, the pellets are transferred from the pellet extruder, to a cooler/drier to eliminate the heat which is produced from pressurization. Moisture must also be allowed to escape the pellets for increased durability in storage and shipping. Pellets are then typically stored in silos or bins for bulk shipping or are processed by packaging systems.

Such pellets are utilized in energy producing systems such as industrial boilers and pellet stoves. Wood pellets are nearly homogenous in terms of energy content per unit of weight.