We demonstrate the use of a Scanning Force Microscope (SFM) for mechanical tests with lithographically defined nanometer sized towers. The employed nanotowers are made of silicon dioxide on top of a silicon substrate with a height of 250 nm and diameters of down to 70 nm, which were broken in a defined way. Such structures/interfaces and their mechanical properties are important for numerous thin film applications e.g. MEMS, electronic devices etc. By using the tapping mode at ambient conditions, the state-of-the-art method established before was significantly improved in terms of reliability and speed. The force threshold for inducing mechanical fracture and fatigue are assessed for individual towers and ensembles of ordered towers. Furthermore, well defined structural features, i.e. material interfaces, have been introduced in the nanotowers to act as well defined breaking points which allows the estimation of the interface strength and in general the influence of interfaces on fracture.