Ionizing radiation causes non equilibrium point defects which allow the development of extended defects in metals such as dislocation loops, stacking fault tetrahedrons, voids, gas bubbles enhanced precipitation or dissolution of precipitates depending on the irradiation condition. Those defects are responsible for mechanical property changes in materials dissolving precipitation in alloys. Small scale mechanical testing especially in-situ has practical advantages such as reduction of dose rate of the material due to volume reduction and basic scientific benefits due to the restricted geometry and selectivity of specific regions in a material. Therefore utilizing small scale mechanical testing on irradiated materials provide practical advantages such as cost savings, but more importantly can provide novel inside in a materials mechanical property change due specific types of defects. This talk features the effect several different types of radiation induced defects have on the mechanical property changes of materials. We will show the formation of slip channels via microscale tensile testing, the change in mechanical properties and deformation mode due to He bubble formation and the change in deformation mode with radiation induced precipitate dissolution. Novel localized implantation using a Helium ion beam microscope further allows to map out the dose-property relationship in a fast and effective fashion.