The coefficient of friction of polytetrafluoroethylene is extremely small, only 1/5 of that of polyethylene, which is an important feature of perfluorocarbon surfaces. Since the fluorine-carbon chain intermolecular force is extremely low, polytetrafluoroethylene has non-tackiness.

PTFE maintains excellent mechanical properties in a wide temperature range of -196~260 ℃, and one of the characteristics of perfluorocarbon polymers is that they are not brittle at low temperatures.

PTFE has a high density of 2. 14 to 2. 20g/cm3, almost no water absorption, and the equilibrium water absorption rate is less than 0. 01%.

Polytetrafluoroethylene is a typical soft and weak polymer. The mutual attraction between macromolecules is small, and the stiffness, hardness and strength are small. It will deform under long-term stress.

Polytetrafluoroethylene is prone to creep when loaded and is a typical plastic with cold flow properties. The creep of PTFE varies with compressive stress, temperature, and crystallinity, with the higher the temperature, the greater the creep. The crystallinity of PTFE is between 55% and 80%, and the creep amount does not exceed 2%. When the crystallinity is below 55% and above 80%, the creep amount increases rapidly.

The excellent mechanical properties of PTFE is that the friction factor is small, between 0. 01 and 0. 10, which is the smallest in the existing plastic materials and even all engineering materials.

The friction coefficient of PTFE increases with the increase of sliding rate, and tends to be stable when the linear velocity reaches 0. 5-1. 0 m/s or more. Moreover, the static friction coefficient is less than the dynamic friction coefficient. This characteristic can be used in bearing manufacturing to reduce its starting resistance and make it very stable from starting to running. The friction coefficient of PTFE decreases with the increase of load, and tends to be constant when the load is above 0. 8 MPa. Under high speed and high load, the friction coefficient of PTFE is lower than 0. 01. From ultra-low temperature to the melting point of PTFE, the friction coefficient is almost unchanged, only when the surface temperature is higher than the melting point, the friction coefficient increases sharply.

Due to the small intermolecular attraction, PTFE has low hardness and is easily worn by other materials. However, as long as the surface roughness of the grinding material is appropriate, the wear amount of PTEF can be reduced to a considerable extent.