In recent years, to enhance flaw detection efficiency when using ultrasonic testing, phased array probes are increasingly used. However, in many cases this can also be achieved by using scanning devices with conventional piezoelectric transducers, which is much cheaper. The purpose of the article is to analyze the design and operation of such scanning devices. The article provides brief information about ultrasonic testing main scanning schemes, describes scanners that have been developed and widely used to perform inspection of welds, base metal of pipes, railcar axles and wheels. It is shown that, for large dimension objects, scanners allow not only a significant increase in the scanning performance but also solve the testing problem in principle, and (for example, when testing railcar axles) change (make it easier and cheaper) manufacturing process, including inspection operations and wage wheels repair. As a result of analysis, conclusions are made about the efficiency of using, in specific and important practical tasks, scanning devices for ultrasonic testing of steel products of different sizes, which certainly does not deny the application perspectiveness of using phased array probes.