In tension band wiring different tensioners and wire-connections are in use. Both of these were examined on tensile force during and after connection with help of a material-testing machine. Additionally the different connections were examined under traction-load. The results show that none of the tensioners for monofilament wire are capable of establishing a permanent tension at the end of the fixation-procedure. Consequently we must ask if the theoretical principle of B. G. Weber concerning tension band wiring is efficient in practice. Only the use of twisted wires in combination with fixation clamps could produce a permanent tension. The limit of elasticity is 2 to 3% for monofilament wires as well as for twisted wires. Further stretching causes plastic, i.e. irreversible deformation in monofilament wire and its connections. In twisted wires further tension stress causes ruptures especially at the border of the fixation clamp. In conclusion extreme active exercise of fractures treated with tension band wiring should not be emphasized.