Normally, the minimum oil film thickness is also the dynamic operating clearance of the bearing. Knowledge of the oil film thickness or dynamic clearances is also useful in determining filtration and metal surface finish requirements. Typically, minimum oil film thicknesses in the load zone during operation ranges from 1.0 to 300 microns, but values of 5 to 75 microns are more common in midsized industrial equipment. The film thickness will be greater in equipment which has a larger diameter shaft. Persons requiring a more exact value should seek information on the Sommerfeld Number and the Reynolds Number. Discussion of these calculations in greater detail is beyond the scope of this article. Note that these values are significantly larger than the one-micron values encountered in rolling element bearings.