A method for spot welding parts formed of conductive metal, comprising the steps of: providing a first part formed of conductive metal and a second part formed of conductive metal; contacting the first part with a first welding tip while rotating the first welding tip around its center axis, the first welding tip including a shaft extending to a distal end and presenting a notch at the distal end, and the shaft including contact surface extending radially outwardly from the notch, including applying no current to the first welding tip for a first period of time; rotating the first welding tip before contacting the first part with the first welding tip during the first period of time; and applying force to the first part by the first welding tip during the first period of time, including contacting a spot on the first part during the first period of time and during a second period of time immediately following the first period of time; applying electrical current to the first welding tip during the second period of time; melting the first part in the spot during the second period of time; decreasing the force applied to the first part by the first welding tip during the second period of time; contacting the spot on the first part during a third period of time immediately following the second period of time; increasing the electrical current applied to the first welding tip while rotating the first welding tip during the third period of time; the rotating steps including continuously or intermittently rotating the first welding tip around its center axis and forming a depression in the first part and a pin extending upwardly from the depression; and rotating the first welding tip about the pin, wherein the pin locks the first welding tip to the first part and prevents the first welding tip from moving radially relative to its center axis during the rotating step. providing a first part formed of conductive metal and a second part formed of conductive metal; contacting the first part with a first welding tip while rotating the first welding tip around its center axis, the first welding tip including a shaft extending to a distal end and presenting a notch at the distal end, and the shaft including contact surface extending radially outwardly from the notch, including applying no current to the first welding tip for a first period of time; rotating the first welding tip before contacting the first part with the first welding tip during the first period of time; and applying force to the first part by the first welding tip during the first period of time, including contacting a spot on the first part during the first period of time and during a second period of time immediately following the first period of time; applying electrical current to the first welding tip during the second period of time; melting the first part in the spot during the second period of time; decreasing the force applied to the first part by the first welding tip during the second period of time; contacting the spot on the first part during a third period of time immediately following the second period of time; increasing the electrical current applied to the first welding tip while rotating the first welding tip during the third period of time; the rotating steps including continuously or intermittently rotating the first welding tip around its center axis and forming a depression in the first part and a pin extending upwardly from the depression; and rotating the first welding tip about the pin, wherein the pin locks the first welding tip to the first part and prevents the first welding tip from moving radially relative to its center axis during the rotating step.