Plastic hardness and rigidity are closely linked. Any material can improve the rigidity of the measures have the effect of increased hardness.

Plastic and will produce different materials with different types of wear and tear. When the mating material is metal, and hard metal (e.g. steel) with less wear and tear when, with the soft metal (such as brass, aluminum, etc.) when worn with the larger. Uneven surfaces such as metal will have a "erosion wear"; such as metal surface is very smooth, it will have a "adhesive wear.” When the mating material is heterogeneous resin, adhesive wear generally larger, depending on the extent of different varieties, such as PBT, PA and POM affinity difference is not easy to produce adhesive wear, and ABS, PP and POM is easy to produce adhesive wear. When meshing the same kinds of resin materials, the friction and wear characteristics than metal or dissimilar resins with much less time, adhesive wear is much greater in this regard is due to the hardness difference is not enough, partly because the resin poor heat resistance, low thermal conductivity than the metal, especially under high pressure rolling, sliding surface temperature anomalies and produce creep, hardness decreased significantly promoted adhesion, while it is easy to issue harsh noise or locking.

Similar material difference between the hardness is not enough, the relative movement easily lead to greater friction, the friction heat generated by a large number of savings in the friction surface, leaving the resin to soften or melt, so that frictional resistance to further expand; there sin and the metal of the difference exists between the hardness, low coefficient of friction at the same time, easy-to-metal thermal conductivity, so that savings in the friction surface of the heat dissipation is reduced, so that the resin softening or melting to occur at higher speeds under load or faster.

Metal bearings, roller hardness is generally higher than the inside and outside the rings, which reduce friction and wear, improve bearing life and load capacity is beneficial. Present in the plastic bearings, rolling little plastic, not rigid or hardness difference may be an important reason.

Reduce friction and wear problems

usually on the friction and wear properties of polymer materials with the friction coefficient, wear rate than the critical PV value and other indicators to evaluate the noise.