Abstract: A data processing system is provided for determining a minimum flange length for a joint to be welded by resistance spot welding. In particular, the data processing system utilizes data for a preselected weld electrode and a set of joint data representative of a joint to be welded to determine whether a set of corrected tip data or a set of uncorrected tip data is to be used in determining the minimum flange length. A method for calculating the minimum flange length is also provided.

Abstract: A method for sizing a weld tool for forming a resistance spot weld to fasten a joint having at least two sheet metal members is provided. The method includes the steps of providing a plurality of weld force curves, determining a governing metal thickness, determining a total thickness of the sheet metal members, determining a plurality of joint parameters, including a weld gap parameter, a thickness parameter, a strength parameter, an equalization parameter and a sheet stiffness parameter, using the plurality of joint parameters to select one of the plurality of weld force curves, and using the governing metal thickness and the selected weld force curve to calculate a weld force parameter.

Abstract: A method and apparatus for limiting the fault current in a portable welding gun comprising a power circuit, the power circuit comprising a circuit breaker and an isolation contactor, the isolation contactor in series with the circuit breaker, the fault current limited by providing a safety circuit, the safety circuit comprising a safety circuit comprising two resistor/relay pairs, the resistor and the relay of each pair in series with each other and each pair in parallel with a contact of said contactor, the resistors sized to limit the fault current in the power circuit to less than 50 ma.

Abstract: A fixture for testing the strength of a resistance spot weld connecting two test strips comprises two identical clamping frames, each having releasable clamps for gripping and holding one of the test strips. A pull bar is mounted on each clamping frame in any one of several selected angular positions. The pull bars are aligned with one another and then grasped by a pulling mechanism to apply a separating force on the two strips. The arrangement is such that the line of the separating force passes through the weld.