This paper describes in the introduction part basic information concerning selection of device of technological line for the aggregates production. It is mostly focused on crushers, which during the crushing have main influence on the outer characteristics of aggregate. Correct functionality of crushers in the process of production of aggregate is crucial and relies on the selection of right mechanical influence on pieces of aggregate during crushing while respecting characteristics of crushed rocks and parameters of chosen crusher. Because of this there are written basic principles of mechanical influence on crushed material of pressure influence (jaw crusher) and with dynamic influence (impact crusher). Later are listed basic requirements for connection of each device within technological line on which follows description of an application for designing of technological line. This application allows designing the technological line with optimization of selection of devices which are using databases of available devices while still respecting listed basic rules of connection to the technological line. This way is ensured requirement of continuous material flow in production of aggregate on technological line.