High power diode laser was the first semiconductor laser used for materials processing. It has found some areas of applications in production. The most promising applications of HPDL in mechanical engineering are in thin steel sheet welding and hardening. The HDPL welding process is at this moment usually performed as conduction limited welding process. In this study the effect of joint configuration and beam properties on the efficiency of welding with HPDL were examined. Joint types tested were bead on plate and butt joint with different joint manufacture. The laser parameters tested were beam intensity, welding speed, incidence angle of laser beam and focal spot size. The tested parameters had an effect on the weld quality and the welding speed. The higher the beam intensity is the higher the welding speed can be achieved. The reliable welding parameters can be established for the welding of various industrial products.