Friction stir spot welding a relatively new solid-state joining technique usually used by automotive manufacturers as alternative to rivets and conventional spot welding resistance has led to the development of a fairly new technique a double-sided friction stir spot welding technique, this method was implemented for aluminum alloy AA6061-T6 by 2 mm thick, with rotating anvil, pin less tool for similar weld joints. Using double-sided FSSW technique increased welded joints strength. The design of rotating anvil and pin less tool for welded aluminum AA6061-T6 alloy has achieved a high tensile strength and avoid a defects such as keyhole. The cross-section welded joints, numerical analysis method explains that the material flow between pin less tool and rotating anvil is complex, using a rotating anvil and pin less tool with FSSW operation, suitable method for welding thicker sheets