Geometrical design and strength check of a prestressed bolt connection, loaded by static or cyclic loading resp., acting both in the axis of the bolt and in the plane of the connected parts. Application is developed in MS Excel, is multi-language and supports Imperial and Metric units. The application includes a table of commonly used materials according to ISO, SAE, DIN, BS, AF ASTM and AISI. Calculation support many 2D CAD systems.