For simplifying the handlings with viscosity-temperature-values fixed points have been defined depicting characteristic viscosities.
These viscosities represent certain technical machining conditions.
The most important fixed points:
Strain point viscosity η=1014,5dPas
Transformation temperature (dilatometric) viscosity η=1013,3dPas
Annealing Point viscosity η=1013,0dPas
Littleton-Point (Softening Point) viscosity η=107,65dPas
Working Point viscosity η=104,0dPas