The paper elaborates possible ways of determining the torsion constant of a wire, and Young's modulus for torsion of the material from which the wire is made. Determination methods are theoretically developed, based on the analysis of material deformation by shear and torsion. After that, the results were experimentally verified by measuring the oscillation period of the torsion pendulum with the possibility of changing the mass distribution, ie the moment of inertia of the pendulum with respect to the axis of rotation. From the obtained results, we calculated the mean value of the torsion constant and its error. We performed the calculation using two methods: the classical method and the LINEST function in Excel. After calculating the other parameters and comparing their values with the catalog ones, we came to the conclusion that it is a kind of soft iron and not steel as we initially thought. The results were not exactly the same as the catalog values but considering the age of the material and the fact that there are several types of soft iron, we can say that the results are fine. We also verified the claim that the torsion pendulum vibrates harmonically for small and large angles of rotation. We tested the pendulum at several angles of rotation ranging from 0 ° to 90 ° and measured a period of oscillation that was approximately the same for all angles. This allowed us to confirm that the torsion pendulum vibrates harmonically for small and large angles in that range. In the end, we were able to prove the assumptions with which we started this experiment and we proved that it is possible to determine the modulus of torsion of the material, and thus its other elastic parameters, using a torsion pendulum.