DCOF

DCOF stands for dynamic coefficient of friction, a dimensionless measure of the resistance to sliding between two contacting surfaces under motion. It is the ratio of frictional force to the normal load during steady sliding and represents kinetic, or dynamic, friction rather than static friction when motion begins.

Measurement is typically performed with a tribometer or sliding sled that applies a defined load to a test surface and moves at a controlled speed. The resulting friction force is recorded and the dynamic coefficient of friction is calculated as the ratio of friction force to the normal force. Conditions such as surface texture, lubrication, temperature, humidity, and wear influence the reported DCOF. Values can vary widely between material pairs and testing conditions, often spanning a range from well below 0.3 to above 1.0 for very rough or highly adherent contacts.

Standards and usage: DCOF is widely used to assess slip resistance, particularly for floors, countertops, and other surfaces encountered in pedestrian environments. Various standards specify minimum wet DCOF values to reduce slip risk, with commonly cited thresholds in the approximate range of 0.4 to 0.6 for safety-critical applications, though exact requirements depend on the standard and context. In addition to flooring, DCOF concepts apply to coatings, polymers, and interface materials where sliding resistance is relevant.

Limitations: DCOF is influenced by testing method, speed, load, and surface conditions, and does not alone determine slip risk in real-world scenarios. It should be considered alongside other factors such as shoe-surface interaction, contamination, and environment.