A new viscosity bathes has been entered the services in Thermal Metrology Laboratory-National Institute for Standards, NIS-Egypt in order to use in maintain and extend the national viscosity scale in wide temperature ranges, international comparison and routine calibration of viscometers. The medium of the bath should be homogenous enough in temperature so many thermal factors taken into account to estimate the temperature gradient, homogeneity,  stability and thermal profile distribution with the  related uncertainty to each parameter. The study carried out by two Standards Platinum Resistance Thermometer (SPRT) calibrated at fixed point according to ITS-90. A number of glass capillary viscometers have been selected and arranged into six groups. The selected viscometers and oils realize NIS viscosity scale in wide temperature ranges from -30 ^oC up to 100 ^oC.