In the recent decade, industrial firms have shifted their focus towards long-term sustainable development that includes both circular economy and net-zero manufacturing. Rotary friction welding (RFW) is a technology that allows for solid state near-net-shape manufacturing. In this study, RFW of MLX®19 precipitation hardened maraging steel was carried out under different weld conditions viz. forge force, friction force and weld speed, and their effect on the mechanical properties of the weldments was studied. The mechanical and microstructural evolution of the weld assemblies were characterised, and the optimised process parameters were determined. The microstructure and texture features revealed the fact that the maximum temperature attained in the weld zone (WZ) was above Ac3, while in the thermo-mechanical affected zone (TMAZ) was in-between Ac1 and Ac3. Examination of the crystallographic texture suggested that the WZ was subjected to pure shear deformation whereas the TMAZ experienced both shear and compressive deformation during the welding process. A 2.5D finite element (FE) model was also developed to predict the temperature distribution and stress-strain evolution during the welding process. The model exhibited the highest temperature and lowest stress at the weld interface. The predicted results from the FE model were compared with an actual instrumented weld (thermocouples embedded) and excellent agreement (error ~ 4.7%,) was observed.