Tested by ASTM D-1044 procedures, abrasion resistance is measured by applying a Taber Abrader with a 250g weight and CS 10-F textured abrader to test specimen for a number of cycles, and then measuring changes in specimen volume and transparency.

Table 1 below shows typical abrasion resistance values for a number of selected thermoplastics.  Lower value equate with greater abrasion resistance.

Hardness

To measure Rockwell hardness by ASTM D-785 procedures, an indenter is loaded with a minor load, a major load and then again with the minor load.  The increased depth of the impression made on the specimen is then measured.  Thus, Rockwell hardness values indicate a material's resistance to surface deformation .  Higher values indicate greater resistance to deformation - thus greater hardness.

Table 2 below shows the relative ranking of major thermoplastics from softest to hardest.

Coefficient Of Friction

The coefficient of friction, determained by ASTM D-1894, numerically represents the resistance to movement when moving against another surface.  Values are givenfor both static friction (the limiting friction between surface just before motion occurs) and kinetic friction (the friction after motion has occured).  The coefficient of friction is the ratio of the limiting friction to the normal reaction between the moving surfaces.

Table 3 below lists the dynamic coefficient of friction of selected thermoplastic  against steel surfaces.  The lower the value, the more slippery the material.