The use of CL oils or CLP mixed oils with additives EP keep low the friction coefficient and protect against oxidisation.

The adequate viscosity grade is relating to the peripheral speed and operation temperature.

The amount of oil required for ball circuits depends on the turning speed estimated between 2 & 5 cm3/hour. In case of bath lubrication for horizontal application, it is sufficient that the level reach the centre of the lower ball.

With the following graphic can be determined the viscosity grade: Example: do = 80 mm Mean speed nm = 500 min^-1 Working temperature = 30ºC

For a nominal diameter of 80 mm. and a mean speed nm of 500 min –1 on the left side of diagram correspond a relative viscosity V1 of 40 mm²/s.

Projecting this value on the right side of diagram, the viscosity required for a working temperature of 30ºC is between ISO VG 22 & ISO VG 32.

The minimum viscosity recommended is 21 mm²/s.