As the piston of internal combustion engine works under the conditions of high temperature, high pressure and high load, the requirements for the piston are relatively high, so the classification of internal combustion engine piston is mainly discussed.

1. According to the fuel used, it can be divided into gasoline engine piston, diesel engine piston and natural gas piston.

2. According to the material of piston, it can be divided into cast iron piston, steel piston, aluminum alloy piston and combined piston.

3. It can be divided into gravity casting piston, squeeze casting piston and forging piston according to the process of manufacturing piston blanks.

4. According to the working conditions of pistons, they can be divided into non pressurized pistons and pressurized pistons.

5. Piston can be divided into car piston, truck piston, motorcycle piston, marine piston, tank piston, tractor piston, lawn mower piston, etc

1. It shall have sufficient strength, stiffness, small mass and light weight to ensure the minimum inertial force.

2. Good thermal conductivity, high temperature, high pressure, corrosion resistance, sufficient heat dissipation capacity, and small heating area.

3. The friction coefficient between piston and piston wall shall be small.

4. When the temperature changes, the size and shape change shall be small, and the minimum clearance with the cylinder wall shall be maintained.

5. It has small coefficient of thermal expansion, small specific gravity, good antiwear property and thermal strength. [2]