Continuous casting has emerged to the most important process for the production of semi-finished steel products. Spray water cooling, as part of the continuous casting process, has major influence on the product quality. For an optimal application of spray cooling, nozzles are operated at certain nozzle parameters, depending on the casting position. With the nozzle measuring stand at Montanuniversitaet Leoben, the cooling characteristics of industrial used nozzles can be determined. The measuring stand allows the controlling and recording of operation parameters like surface temperature, water flow rate and air pressure. For this work the spray water cooling in the secondary cooling zone of a slab caster, operated by the industrial partner voestalpine Stahl GmbH was characterized. The measurement program included nine different cooling nozzle types which were operated according to several cooling strategies. Important information about spray cooling was gained from the determination of the water distribution (WVT) and the measurement of the heat transfer coefficient (HTC). To improve the understanding of the influence of droplet velocity and size, the methods of laser diffraction analysis and high speed camera measurement were used. The experimental surface was adjusted to investigate the impact of certain surface conditions like scale and surface roughness on the cooling performance. From over 450 water distribution and 1300 HTC measurements a comprehensive picture about spray water cooling could be developed. To finally implement the found results into solidification models, a correlation for the calculation of the HTC using the most important influence parameters was developed.