A system and method for using Friction Stir Spot Joining (FSSJ) to join workpieces made of Advanced High Strength Steels (AHSS), wherein a first embodiment is a FSSJ tool that has no surface features, and wherein the rate of rotation of the FSSJ tool is much higher than is used in other FSW techniques to thereby reduce torque by causing plasticization of the AHSS on a small scale, and in a second embodiment, conventional FSSJ tools can be used at conventional FSSJ speeds if the FSSJ tool is manufactured from conductive tool materials having a high hardness, and heating of the FSSJ tool and/or the workpieces enhances the ability of the FSSJ tool to functionally weld the AHSS.