Pin-on-disc testing is a commonly used technique for investigating sliding wear. As the name implies, such apparatus consists essentially of a "pin" in contact with a rotating disc. Either the pin or the disc can be the test piece of interest. The contact surface of the pin may be flat, spherical, or, indeed, of any convenient geometry, including that of actual wear components.

In a typical pin-on-disc experiment, the coefficient of friction is continuously monitored as wear occurs, and the material removed is determined by weighing and/or measuring the profile of the resulting wear track. Changes in coefficient of friction are frequently indicative of a change in wear mechanism, although marked changes are often seen during the early stages of wear tests as equilibrium conditions become established.

The main variables which affect friction and wear are velocity and normal load. In addition, specimen orientation can be important if retained wear debris affects the wear rate.

Most commercial pin-on-disk testers use high loads (e.g., 100 - 1000N) obtained with a dead weight and large areas of contact. In the NanoTest, a lower, continuously variable load (from the mN range to 20N with the high load head) and a smaller pin are employed to achieve equivalent pressures. This reflects the current movement towards lower load, smaller scale tribology testing.

NanoTest Pin-On-Disc Features